Well, it depends actually, what you really want. I personally know no game, that has no sex at all, be it lesbian or straight sex. And most games, that have very good exhibitionism and casual nudity are visual novels.
There are a some games, that nevertheless may fulfill, what you're looking for. I show some and tell, what happens:
Sunville: is a primary lesbian exhibitionism visual novel in a school setting in a world almost full of females. The female MC and her complete surrounding are constantly more convenient showing themselves off in public situations. There is definitely lots of mentioning it and the characters get aroused by what they do. So there is still sexual activity in it, but definitely nothing that even looks like rape.
Ariane in paradise: Visual Novel with male or female MC: you spend your holidays in some space, where clothes are optional. You meet another girl and spend some time with her. If she likes you, you spend more time together and have also sex with her. But that is not for being nude. If you make it to day 3, the last day of the game all your naughty dreams might come true. This day has no sex at all, but really flashed me. My favourite scene on that day was a gymnastics scene. But whether you see this depends on your decisions during the last day. But it isn't easy to get through to day 3. You can get some game overs, if Ariane likes you don't raise stats enough, you make some bad decisions or don't learn enough about Ariane. The game is mostly first person perspective, so you don't see much from the MC. The reward comes mostly from getting Ariane to do and watching Ariane doing things. Hard to describe, but it was great just for the exhibitionism that was presented.
Coming of age: This is a rpgm-game about a young girl getting constantly more shameless. There is definitely much sex in it, but I think, most (if not all) of it is avoidable. The sex is not while the exhibitionism scenes. This is somehow seperate. You can't go completely nude out of the house by now, but have some exhibitionism contests in which you go streaking. The last scene in this regard is really nice
and you can go out of house without underwear by now, which is often visible to others. And as far as I remember, there is also no touching during exhibitionism scenes, but often people mentioning it, but mostly positively. Progress is mostly done through stats, which you must grind, but you can also use an old save and watch older scenes in a recreation room.