So, haven't read anything similar but I am always happy to do research for other. It helps me find new reads as well. Let me know if this is right:
1. https://www.mangago.me/read-manga/i_m_banging_my_rival_from_a_parallel_world/
2. https://www.mangago.me/read-manga/from_the_front_line_base_with_love_verticomix/
2. For this one, I found something with a scene similar to what you described but I'm unsure if the rest of the details align..
https://www.mangago.me/read-manga/bitten_by_moonlight/
Third one can be 'crush and burn'
tysmmm
thank you thank you it was crush and burn hehehehe
1. Rivals/enemies in highschool meet themselves from alt world where they were banging and were lovers
2. Scientist and Soldier fall in love in a military base, the bottom is a scientist who got his work stolen and was hated by the top at first
3. Guys who are reincarnations of Gods who are being pestered by a little vampire the 'moon god' saved from years ago, it starts with the reincarnated bottom getting mauled by said vampire and waking up in a cathedral(?) or church where the best healer(top/also reincarnated god) shows interest in him because he needs a moon or something idk i forgot, last I checked they were gonna sacrifice themselves to stop the cycle(?) of reincarnation and death