NOOOOOOOOO HOW COULD THEY DO THAT !!!! that's so sad... what game was it??
i think this is also a common trope because especially if it's a fem gay / masc straight BL situation you have the whole "can you really get it up for a man" thing they need to prove, though that's more of an issue with fem bottoms lol. but still!!

ok i have a few recs

• my partner's tastes & fetishes - his hair isn't LONG really, it's just above his shoulders, but it's longer than the uke's and he's more feminine than the uke imo

• Even If There Is No Rainbow Tomorrow / Ashita Niji ga Denakute mo. drag queen top, so his long hair is a wig and he does have short hair, but the couple continues to do stuff with him in drag mode so i count it.

• black eagle in the sahara (and connected stories by emu soutome) - i hesitate recommending this because it's a slavery storyline which i hate. however, once you're past that i do like the characters (including side characters), and her art is absolutely gorgeous and loki is one of the most exquisitely beautiful bottoms in existence imo. and it's got a proper long-haired seme :)

• Hi Manyuaru Ren Ai - very short one-shot but beautiful fem first-time-seme!!

other long-haired feminine tops for manga i haven't started or started but dropped:
- bad friend
- The Northern Grand Duke's Secret Contract
- moon of the devil world
- ero wizard's research journal

... that's all i can think of. we're seriously lacking 😩 i'm constantly checking tags and trying new manga so if i find more i will share!