Reunion. After the MC and his harem move like 2 or 3 updates ago, some girls wear lingerie or underwear around the house all the time, some skmpy shirt and shorts, some topless, cant remember the last time any of them swam in a bikini, they all seem to sleep nude even outside of sex.
from what I remember there's Japanese artform centered around partial nudity, nip slips, short shirts, etc. I'm all about the arousal factor multiplied exponentially from a cute girl being partially clothed.
I love this trope as well. A lot of trainer games with good wardrobe systems can scratch that itch for me, especially if there's unique transitions between the NO! to fine... to absolutely! phases of skimpier and skimpier costumes, though unfortunately that's usually the extent of it in those games.
It does come up occasionally in Now & Then, which I can highly recommend anyway. The MC initially just tries to survive in a (pretty dark) zombie apocalypse with his adult adopted daughter. But then they become a couple. When her best friend joins them, it is the foundation for an ever increasing harem. For part of the time the story has the character of a road movie.
Definitely HHS, especially with the extended sister mod (don't remember the actual name). I'm also pretty sure that you can get the girls in Rogue Like Evolution to walk around naked once they are lewd enough. Can't think of anything else right now off the top of my head.