Parasitic panties would have you trained in a heartbeat. You’d wake up terrified, obviously, utterly unable to get them off or even peek under them, but you’d feel their warm wet slippery interior feeling you up.
And despite the absurdity of the situation, you’d still have work and errands to run. You’d be an anxious mess, wracking your brain for a solution. But eventually a slutty thought would pop into your head, it would eventually. And barely noticeably, the panties start rubbing your clit.
You think you’ve lost your mind; that doesn't make any sense. You have to focus. You need to get these off. They do feel… weirdly good, though.
And the panties rub you just a little faster. You don’t know it yet, but you’ve already lost this long, drawn-out battle of wills. Because it will just keep happening, and soon it won’t just be thoughts.
Soon you’ll be so pent up that you’ll just say that inappropriate thing that popped into your head just to be rewarded by a tendril sliding inside you, and then another silly idea pops into your head. Would I fuck you with that tentacle if you did it again?
It only gets worse from there. When you drunkenly flash a stranger your tits on a night out, they start vibrating. When you make out with a stranger in the bathroom, they start thrusting inside you. And when you drunkenly get down on your knees to feverishly eat out the very flustered bartender, they almost make you cum.
You’re so far gone at this point that you don’t even realize it. But the panties are only going to make you sluttier, dumber, hornier, and you’re never going to get them off. But that's not a concern anymore since you don't ever want to take them off.