She woke me up just a bit later that evening. As soon as she saw my eyes open she started asking about dinner. I guess I was relieved that she was the same as ever, because I remember cooking her an even bigger meal than usual that night. It wasn’t long before she was asking me if I wanted to do “that” again, though. She obviously didn’t think too much of it; to her it was just something fun, but I couldn’t get over the feeling that it was something I shouldn’t do so often with my sister. The first time, I had just been helping her along, there was nothing wrong with that. I had always tried to be there for her and help her get over her problems, that was nothing different. But I tried to convince myself that she should help herself along afterwards. I told her that it was a game she could play by herself. And she did, a lot, but she didn’t stop asking, always telling me how it was better with her big sister around. Telling me how much warmer and safer it felt with my wings around her.
 
It didn’t get any easier to say no. All she had to do was mention that first time and my mind would race back to the feeling of her heat on me, the look on her face as she came in my arms, just how good it was to hold her and touch her like that. Even when she wasn’t asking, I was looking at her in a whole new light. I often found my eyes wandering to the creamy skin of her thighs, dreamily admiring just how fluffy her feathers covering the rest of them looked. Those daydreams got harder to snap myself out of the more vivid I let them become. I kept having to excuse myself and leave her alone just to get those thoughts out of my head, but nothing was working.
 
My sister carried on happily as ever, though. She might have wanted me in there with her, but she was spending plenty of time in her bedroom getting to know her growing body. Sometimes I’d sit outside her room, ear to the door and wingtip idly stroking. I thought it might give me some relief if I could just enjoy listening to her soft panting, but of course it only made things worse. I was pretty close to breaking down and going in there with her again.
 
It didn’t help that the other girls my age were starting to talk about their sexual encounters with some of the men from nearby villages. Some had even brought back men themselves. I didn’t have any stories I could share with them, I was too busy dealing with my own fantasies to actually find men myself. Some of them talked about experimenting with other harpies, but I didn’t think it would be right to talk about my own sister that way. I kept my thoughts to myself, and they nearly drove me crazy without an outlet.
 
Finally, though, I found an excuse. I overheard one of my friends talking about how her husband had tried using his mouth on her and just how good it felt. It’s not hard to guess where my mind took that knowledge, and it was hard to make it through the rest of the day. I kept my legs tightly closed to hide how wet I was getting thinking about either my sister’s lips on my sex or mine on hers. The walk home with her was even harder. My head was spinning, but by then I already knew what I was going to do. This time when we got home, I was the one who asked if she wanted to do “that” again. Her eyes lit up and she nearly tackled me with a hug.
 
“Oh thank you sis, thank you so much, I was so worried you’d never want to again!” She raced off, nearly skipping all the way to my room. I couldn’t help but wonder as I followed her. Did she really not feel like anything was wrong with doing this?
 
By the time I caught up with her, she was already sitting on the edge of my bed, legs parted ever so slightly and oh so inviting. I did my best to keep my thoughts clear for just a moment longer and explained that there was something new I wanted to try, and that this time I’d take care of everything for her. She bounced with excitement.
 
I knelt in front of her, leveling my face with her waist. Without a word I nudged her thighs open, and it wasn’t hard to tell that she was just as ready for this as I was down there. Her skin glistened where her arousal had leaked out and been massaged in. I trailed a feather lightly over her damp crotch, and she squirmed impatiently over me. “H-Hurry up, sis,” she whispered. All too eager to do just that, I leaned in and gave her sex a tentative lick. I was rewarded with the warm taste of her juices and a yelp. That was all the motivation I needed, and I kept at it with a smile. The slightly grainy texture inside her tickled my tongue just a bit as I let it slip farther into her. Her legs gently wrapped themselves around me as I bobbed my head, licking up every drop of liquid that poured out. The feeling of it dribbling down my chin was ecstasy itself, and I was far too lost in it to keep from rubbing between my own thighs while I listened to her coos and breaths.
 
Rather suddenly, her legs unwound their grip and her wing pushed my forehead away. Enjoying myself too much to stop, I just tilted my head up towards her. Her voice came out shaking. “Do- do you think that, uh, that ooh...” Her whole body shuddered as I slowly licked along an apparently sensitive spot. I made note of it. “Could I do the- the same thing for you?” I popped back a bit, my interest piqued, and asked her what she meant. “Um, h-here, just lay down on the bed,” she suggested quickly, obviously ready to get back to things. I did so, and in a flash she was on her knees over me, facing away. She leaned down so that her head was in my crotch, and pet her own slide back towards my face. I’m still surprised she managed to come up with that position on her own. I wasted no time in grabbing her cute butt with my wings, pulling her in closer and tasting her sex again. She squeaked and started to bury her face between my legs, but came up just as soon. “Wait, how do I...”
 
I pulled away for just long enough to tell her to do whatever felt good when she saw me doing it, and leaned back in. When her tongue brushed my clit, it was the first time anyone else had touched me down there. I guess I wasn’t ready for such a rush, because I think I started to squeeze her head with my legs and moan into like I was possessed. Everything became a blur of taste and fluid and sensation, if I licked faster she’d do the same, if I started to take longer strokes her tongue would mimic that too. For a while that was our whole world, we writhed there as one body of feather and skin, floating in an endless ocean of pleasure. I came again and again, and her spasming and filling my mouth with juice told me she was enjoying it just as much.
 
Eventually she rolled off of me, and turned up so she was face to face. We were both panting, and just stared at each other for a minute. The look in her eyes was something between awe and adoration. “Thanks, big sis,” she said between heavy breaths. “I love you so much.” Without really thinking, I grabbed her in my winds and pulled her in close, locking my lips with hers. She froze up, but quickly relaxed into it, wrapping me up as we laid there tasting our own juices in the other’s mouth. I didn’t care about right or wrong any more. I pulled away after a long kiss, and we laid there quietly, covered in each other’s feathers. She was my sister, and our love was way beyond worrying what anyone else thought of what we did.