Kinky smut and hentai with either a major theme (or 1+ scene that I found insanely hot) of having sex in public, around people, in front of people, watching people have sex, etc.
Honorable mention to my favorite smut: Nanako to Kaoru. Specifically chapter 2’s voyeur scene and chapter 3’s phone sex scene in public. 👌 (tw incest, age gap)