It's Called an Erection

It had been a long while since Elisha first tried copying his dad, about a week or two. He wanted to try it again, it had felt so good. At the same time, he had a nervous feeling nagging at him. A smidge of anxiety in the pit of his stomach because he thought this was something only adults should be doing. The puppy started getting a little avoidant with his mother, not talking to her as much, hanging out alone in his room more often. It was out of character, so his mother began to worry. 
Elisha was too on edge about his new discovery, unable to do anything with his mother home. He worried that she might hear him or enter the room. It was constantly on his mind though, and after a few days, he found himself getting excited without touching. The puppy would just think about it and start to get hard, a little tent in his jeans. Eli did his best to hide it, but he wasn't quite good at it. His guilt was obvious like a child caught with his hand in the cookie jar. By the time about a week and a half had passed, Elisha's mother started to notice the random erections. It flustered her some, embarrassed, unsure how to have a conversation with her son about it. His mother knew this day would come, but she just didn't expect it to start happening so young. Rather than talk to Elisha about it, she resorted to telling his father. She thought it might be better if this was a father-son conversation rather than a mother-son conversation. 
When Jack picked Elisha up for the weekend, he did his best to pretend he had no knowledge of Elisha's little... issue. He opened the car door for him and buckled him up, ruffling his hair and giving his forehead a soft smooch. The older german shepherd got into the driver's seat and buckled himself up before starting the car and driving off. He made Idle conversation on the car ride back to his house, wanting to wait until the subject... came up, before talking to Elisha about it. No reason to make the puppy uncomfortable his whole weekend. Jack just hoped the conversation wouldn't embarrass him too much. On top of that, he was nervous this might have something to do with Elisha catching him weeks ago. If that was the case, he prayed it was just innocent curiosity that brought his child to begin getting aroused rather than... less than moral thoughts. 
He didn't like considering that maybe it had gotten Elisha excited, seeing his father rubbing at himself under the blankets on his bed. Surely it was the first sexual thing the boy has ever seen, so it would be somewhat understandable if it had gotten him excited. It would only be a problem if Elisha developed some sort of attraction to the man, and Jack felt conflicted about it. Obviously, he didn't want it to happen, but he was conflicted. Unsure how to respond if Elisha eventually voiced an attraction to the older man. Jack wouldn't allow such a thing to ever go on of course, no matter how old his son got, but he knew it would probably be real upsetting. getting that sort of rejection from someone so close would definitely hurt. He loved Elisha more than anything, so he had to consider how to steer Elisha away from himself as an object of attraction. Best to come up with a plan, just in case. 
jack wondered if maybe he could... give Elisha one of his magazines, if that's something he wanted. His face heated up just thinking about it, he couldn't give his eight-year-old pup a porno mag, that would be very much illegal. And immoral, he had to remind himself. At the same time though, he remembered being thrilled when he found his own father's stash of magazines as a pup, around ten years old or so. He couldn't help but take one, and he looked at it almost every night. A lot of pages ended up getting stuck together, he recalled fondly. Then felt a little sick with himself after his brain flashed him an imagined image, Elisha stroking his little puppy penis to one of his daddy's magazines. Alright, so that wasn't a good option, Jack decided. 
Elisha seemed oblivious to Jack's internal struggle on the way back to his second home, kicking his legs some in the car and humming. His eyes stayed glued to the window. Always such a curious little pup, he loved watching everything pass by as he rode in the car. The pretty flowers, the other animals walking or jogging, working in their yards, houses and buildings. Eli's big eyes just loved taking in everything, his tail wagging quickly. It made Jack relax a bit when he looked over and saw his son like that, relaxing. Everything would be fine, he was sure. Elisha was just entering the awkward and confusing time of arousal a bit early. He was gonna be a supportive parent, nothing wrong with the puppy indulging in a little self-love as long as he's alone in his room. 
The first thing Elisha did when he got to his father's house was make his way to the living room. He cuddled up with one of the couch pillows, tail thumping against the cushion some before looking over at Jack as he entered the room.
"Will you watch some cartoons with me, daddy?" The pup asked him excitedly, giving a smile. Elisha was relaxed today, just glad to be spending time with his father again. He loved his mom, but he especially loved visiting his dad on the weekends. He wished his parents were still together so he could see them every day, but he tried not to dwell on that. He tried to look at the bright side, at least his parents were still friends.
Jack chuckled and gave his boy a nod, ruffling his hair gently as he walked by to sit on the couch next to Elisha. The man put an arm around his son's shoulders, pulling him close to his side. He loved getting to spend time with his boy, smiling some as he gave Elisha the television remote. "Of course, kiddo. cartoons sound great."
The older german shepherd sat and watched with his son for about an hour, letting the pup stay curled up at his side, his little tail wagging in excitement as he watched one of his favorite shows. After that, he decided it was about time for him to start making dinner, giving his pup a kiss on the forehead before getting up. He retreated to the kitchen, Elisha too enthralled in his show to mind too much. His belly gave a grumble as well, not about to protest to the idea of dinner.  His eyes just stayed focused on his show though, giggling when something was funny. His cheeks got a little flushed though, one of the cartoon characters was a puppy around his age, and he found the other boy cute. He had a little crush on some of his favorite characters like most pups get when they're little. While that was going on, jack started boiling some noodles and cooking some hamburgers for him and Elisha.
Elisha squirmed a little bit as his eyes scanned the screen, getting that good funny feeling as his hips rubbed against the pillow he was hugging just a little. He was quickly erect in his jeans, his little canine cock giving throbs. He did his best to keep still and ignore it, but his hips started to instinctively rock up against the pillow just a little. His body shivered some and he bit on his lip hard so he wouldn't make a noise, worried his father might hear him in the other room. It felt so good... Elisha thought that maybe if he just tried to be really quiet, his daddy wouldn't notice him doing this.  The little german shepherd held onto the pillow tighter, hips starting to buck up against the pillow, breathing heavily through his nose. He let out a few quiet little whimpers, rolling up against the pillow, nuzzling it affectionately. He was so hard, so excited. It just felt so good to hump something, he couldn't help it.
Jack's ears twitched a little bit as he heard the fumbling around in his living room, eyebrows furrowing. He wondered what his pup was getting up to when the sound of movement didn't stop, turning the flame down on the stove before shifting to look over at his son, eyebrows shooting up. The kitchen was connected to the living room, so Elisha was basically humping a couch pillow right in front of his father. The older canine was tense and flustered, turning his back to the pup so he could think. He had to collect himself, contemplate how to go about this. He knew he should acknowledge it at least, or ask Elisha to go to his room to do that, but he was worried he might embarrass his boy. He knew his son probably thought he wouldn't even notice while he cooked. In response, Jack decided to continue cooking, let Elisha ride this one out in the living room just this once. 
Elisha kept up his actions, too wound up to really think about the consequences now that he was actually stimulating himself again. He shifted to get into a better position, or at least he thought it would be. Must have been his canine instincts, because the boy shifted so he was on top of the pillow, humping like a dog trying to mount. Eli was panting just a little bit, struggling to keep his breathing quiet as he quickly thrust his hips against his daddy's couch pillow. He nuzzled against it and held back a pleased little noise, hugging it tightly. It smelled good, warm and safe, familiar, home. For some reason that made it feel even better thrusting his little clothed cock all over it. Elisha didn't dare to take his penis out though, too nervous.
Jack glanced back at his son when he heard him shuffling as he changed position, looking before thinking on it. He was a bit tenser, his face a little pink as he saw his little puppy eagerly humping on his couch pillow. The man laid down with that pillow... guests sat with that pillow... now his boy was going to orgasm with it. Jack wasn't going to be able to forget. He looked away quickly, hoping Elisha would finish soon, or maybe tire himself out. By now, the little shepherd had his eyes shut tight, overwhelmed with pleasure as he humped even faster, making quite a commotion. He assumed if his dad hadn't caught him by now, the older canine wasn't about to catch him. He was so close too, affectionately nuzzling the pillow, breathing in the scent of home and his dad. His little puppy penis throbbed hard as he realized he could smell his dad's scent on the pillow, his breath hitching. His hips jolted and his whole body shook, cock throbbing erratically as he had his second-ever dry cum. His hips bucked hard against the pillow with each little aftershock, struggling not to make noise.
Jack just couldn't resist the urge to glance over at his son again when he heard the puppy's breath hitch, shame welling in the pit of his stomach as he felt the tip of his cock slip out of his sheath. Seeing his son finishing against his own pillow? Hips convulsively thrusting like that as he finished? it stirred something in him that he hadn't been aware of until now. He'd never had an attraction to any cub or pup before, but after seeing his son like that... he wanted to see the puppy hump some more. Jack shoved those thoughts deep down, telling himself he would refuse to acknowledge them. It wasn't right, Elisha was just curious and innocent, finding things out like a normal pup. Jack couldn't ruin that for him, couldn't hurt his poor boy. He cursed himself for allowing that sort of thought into his mind, though the tip of his cock stayed unsheathed, nothing to cause notice though.
Elisha laid on top of the pillow for a couple of minutes, catching his breath and just relaxing before he sat normally again. He yawned, feeling sleepy like he had the first time he rubbed on his penis. It gave him a chill thinking about it, his little cock giving a weak throb in his jeans. He'd rubbed on his penis the same way his daddy did, for some reason that thought gave him tingles. He felt odd about it, but it made his heart race some, excited. He still had a noticeable- though tiny -bulge in his jeans though, it would take a few minutes for his puppy knot to go down again.
The older canine didn't turn again until he was done with his cooking, setting the table. He made himself and his boy a plate of mac and cheese with a burger, sitting down at the table and calling his boy over. By now, Elisha's knot was almost down, but the little bulge in his jeans was still noticeable, Jack found himself looking at it as Elisha came to the kitchen table. He was about to speak, but then he heard his son first.
"Mac and cheese? my favorite!" He said in excitement, his little brown and black tail wagging a mile a minute. He quickly started to dig in, giving a content hum. Jack only chuckled and smiled, now feeling somewhat nervous about bringing the subject of erections up. He decided he should wait until after dinner, maybe.
Once the two were finished eating, Jack wiped his muzzle with a napkin and cleared his though gently, hands folding on the table. He offered his son a reassuring smile. "So, Eli. I noticed when you... came over to the table, your jeans seemed... pretty tight on you. It's alright, it's okay, please don't get embarrassed. I just. Wanted to make sure you know it's okay. It's called an erection, or a boner. Lots of boys start getting excited like that when they're your age or a little older. Just make sure you keep it private, okay? If your body gets excited, it's okay to go have some alone time in your room. As long as you keep it to yourself, okay pup?" Jack kept his voice soft and even, wanting to make sure Elisha knew it was alright. He just didn't want to catch Elisha humping out in the open again. Well... maybe part of him did want that, but he was choosing to stay on the good parent path.
Elisha felt deeply embarrassed as soon as his father started to talk about him, face going a deep red. His eyes were glued to the floor, kicking his legs back and forth nervously. He was relieved that his dad still didn't seem to know about his actions in the living room, but embarrassed his dad saw the lump in his pants. At least the older canine was so reassuring, making his puppy feel less upset about it. He gave little nods, shyly looking at his father, looking away again quickly.
Jack got up and collected their plates, pressing a kiss to his son's forehead before starting to do the dishes, letting Elisha go off to do his own thing. The younger pup hesitated to get off his chair, lingering around his dad before going to watch tv again. It wasn't long before the shepherd puppy was asleep though, tired from his shaking orgasm earlier. 
Once Jack finished with the dishes, he found his son curled up on the couch, fast asleep. His head was resting on the pillow that he hadn't touched, the other pillow left abandoned. First, the father moved to grab jack a blanket, wrapping it around his son, tucking him in comfortably and leaving his cartoons on. He figured it was the weekend, why not spoil him. After that though, he found himself staring some, his eyes trailing over the peacefully asleep puppy. Jack's cock tip was poking out of his sheath again, giving a tiny throb. His hand slowly moved to his cock over his pants, giving a rub, one more rub, then he freezes. This was bad, he couldn't do this. Jack felt dread, shame. He was about to rub out, standing in front of his sleeping son. His eyes darted to the pillow, and his cock slipped out a few inches. The adult shepherd leaned down to kiss Elisha on the forehead before grabbing the forgotten pillow, taking it back to his room.
Once jack was alone in his own space, he made sure to lock the door this time. He was sure he would be fast anyway, getting more aroused by the moment. His next action was to quickly undo his pants, pulling his canine cock out, now fully hard and throbbing out in the open. Jack looked at the pillow, eyes shutting for a moment as he remembered the way his son looked as he shook and climaxed against it. The older dog shivered, shooting a little pre-cum out when his cock throbbed again. He brought the pillow to his face and sniffed it, smelling his son's scent since the pup had been rubbing all over it. 
Jack put the pillow on his bed and got himself into position, pressing his cock down directly on the fabric. He hasn't humped a pillow since he was a teenager, but knowing his son had just fucked this? He was almost ready to cum. The adult shepherd started to thrust on it erratically, thick canine dick throbbing and shooting pre all over it, smearing it in as he humped. Jack panted and leaned over it, picturing his son nuzzling against the pillow after he cleans it. It was so hot, thinking his son might rub his face where his penis has rubbed on. His hips jerked erratically, stopping to grab his cock and stroke it fast. He aimed for the pillow, his knot swollen, going tense as he shot thick loads of cum all over the pillow. That container of fluff was sure to be full of Jack's scent now. Even after jack was done cumming, he rubbed his cock on the pillow some more, smearing his cum into the fabric. 
A shaky breath left the man as reality set in. He just fantasized about his little pup, and he... really, really enjoyed it. For now, he had to hide the pillow, making a mental note to clean it later. At this moment, he only felt guilty, placing it in his closet before moving to climb into his bed, waiting for his cock to resheath before he redid his pants. It took Jack a long time to fall asleep that night.