It's possible to get naked at the party, but it's event based, unfortunately. As you mingle with the other students, you'll eventually end up being asked to ditch your top. Then later your bottoms. Sounds like a lot of save scumming to trick the RNG to get the scenes required.
Can't remember how mtf and too lazy but as far I could think, Have exhibitionist needed as per 4+ and more advance of its traits. Not odd enough, Only flat tits fine but skills needed and such for that to be able except streaker at night. But if i'll have my transman later, i can try cheat up and checked it out myself if, i don't forgot this thing.