So I read this one a while ago and can’t remember what it’s called. But I remember the premise of it.
There’s this guy who can hop between universes and as he goes along he can see if any given women is compatible with him this results in a massive harem of course. If any one needs more details I’m pretty sure I can think of a few more
Source: reddit.com/r/Erotica/comments/zxxkrw/looking_for_a_fic