Muffet was a monster of very humble, or at the very least, simple desires. Money was, for the most part, her lone motivator, and was willing to do anything to get it. This usually meant selling pastries of questionable origin at her bake sale, but sometimes she resorted to assaulting passersby impolite enough to walk by her without making a purchase. 

She was willing, however, to do anything it would take to net herself some gold if someone offered. She found, one day, a note, dangling from a stray strand of her web.

"Ahuhuhu, what could this be?" she said, the violet-skinned spider snatching it up in one of her many arms. 

She read it, and this mysterious client, although remaining anonymous, seemed fairly open about what they wanted. To put it simply, they were looking for her to do an erotic performance, with some fairly unusual things involved. It wasn't anything Muffet would be unwilling to do, especially for the astounding amount of gold she was being offered for it.

And everything she needed would be provided at the designated location. It seemed too good to be true. 

And so, Muffet arrived at her destination, an unassuming little building somewhere in Hotland she had never visited before. She entered through the back door, coming to what looked like a stage at the back of the room with a large pole in the middle, pretty much exactly what she was told she'd see there.

And next to the pole was a small box, with a special garment inside.

"Open it" a voice said from the darkness, clearing being filtered through some voice-changing device. Muffet could care less who this client actually was, and honestly, if the voice was one she was familiar with, she wouldn't have put the effort into figure out who they were.

She tore open the box, opening it with two of her limbs and removing the item within with other two. It was a diaper, something the message had informed her of, a cute, puffy white nappy, clearly personalized for her, judging by the small print of a spider on the back.

She put it on, removing her pantaloons. She turned around, giving her butt a playful wiggle towards her anonymous client. 

"Like what you see?" she teased. 

"Oh, yes" the voice replied. 

Muffet recalled what the mysterious client wanted her to do next, and so, she turned around, squatting, legs spread slightly. Her cheeks turned bright red as she began to mess herself, her diaper tenting out in the back with a large, naughty bulge. 

One of her many arms grabbed and squeezed that naughty sag, moaning and chuckling to herself. Of course, she knew there was one more step to her client's request. 

She approached the pole in the center, beginning to gently grind her padded ass against it, the room filling with the sound of squelching and crinkling. The sheer lewdness of the sensation of her mess pressed up against her ass caused her to moan, her mouth hanging open as she began to drool. 

At this point, it was less about pleasing the client, or even getting the gold, she was simply enjoying herself. 

And she continued, ass pressed up to the pole, continuing to fill her diaper with more mess as her bulge swelled and a brown stain began to form.

And so she continued, grinding her ass against the pole until eventually, she reached a massive, spidery orgasm, her sexual juices filling her diaper along with her filth. 

Panting, she watched as a hand emerged from the darkness, handing her a box filled to the brim with gold.

She took it, turning to her mysterious client and chuckling. "I might even do it for free next time~"