With how much partying the pair of you did, it was pretty inevitable that you and Jenny would fool around, and it was just as inevitable that as soon as you were finished you'd pass right out. You slept in until something like 2 or 3 in the afternoon, waking up with a raging headache, and taking a while to remember where you were and gather up your clothes. Jenny was already up, wearing just a bathrobe several sizes too small for her, brewing up some coffee and splashing hot sauce on some eggs.
"Morning there sleepy! That was a heck of a time. Definitely gonna have to hook up again some time."
You muttered an enthusiastic reply, rather distracted as you unmade Jenny's bed looking for where your dick had gotten off to.
Seeing you, Jenny chuckled a little. "Looking for this?" she grabbed your missing member from the counter, by the hot sauce. "I'd heard from my friend Rosa these just... pop off like this lately? It's really wild to see it though. Figured I'd wash it off for you... after having a little fun with it in the shower, hope you don't mind. How the heck does it work though? I mean... it doesn't make sense that they come off, but how do you get them back on again after? I tried popping it back while you were asleep but it wouldn't stick or anything."
She was talking with her hands as she went on about it, gesturing wildly like your cock was a baton, and as she finished, she was pointing it at her own crotch, bringing it close enough to snap into place just as you were about to warn her to be careful with it.
"Oh damn!" she shouted. "Why didn't that work with you? And I mean like... I can actually feel it, like it's a part of me!" She gave it a quick tug, leaving a very shocked expression on her face. "... OK how do I get this back off?"
You really needed to deal with your hangover some before you could explain things, but eventually you passed along everything you'd pieced together over the course of the week.
"So... I'm stuck with this thing between my legs until tomorrow, basically?"
"Well no," you explained. "Just... relax for the next half hour or so and... forgive the language, but jack off with it, and it should pop right off again."
Jenny stared at you. "OK no. That's not happening. It is weird enough having this thing here, there's no way I'm doing THAT. I know it's kind of a fantasy a lot of girls have, but I'm not one of them. I'm just gonna... tuck this away as best I can, go about my day, really try not to think about it, and give it back to you tomorrow."
You had some pretty strong objections to that, but she shut you down hard with some pretty pointed lecturing about consent, not being able to force her to do anything sexual whether you were involved or not, and asking if you'd be OK with it if she just stuck it in you to get it off again. That and you really just met, and it was already pushing things hooking up the night before.
Furthermore, Jenny had plans for the rest of the day, and insisted she absolutely could not cancel them, and you couldn't hang around all day. Once again, she made it pretty clear this was non-negotiable. You did make plans to meet back up first thing the next morning, but for now, you were heading home, with a vagina.