As in he wants the smut?? Cos if yes then https://www.mangago.zone/read-manga/sono_suki_honto/
If he wants to try shounen ai then https://www.mangago.zone/read-manga/karasugaoka_don_t_be_shy/
Start with shounen ai? Some ppl think yaoi =BL, so maybe something without those parts are OK.
Try:
Salad days (slow paced, touching, more on subtle romance)
https://www.mangago.zone/read-manga/salad_days_tang_liuzang/
Southern Bird and Northern bird (link below, comedy, subtle, very cute, short chapters, main characters are two male birds)
https://www.mangago.zone/read-manga/southern_bird_and_northern_bird/
Global examination (adapted from novel, action, I heard great things about it)
https://www.mangago.zone/read-manga/global_examination/
Here you are
https://www.mangago.zone/read-manga/here_u_are/
Social temperature
https://www.mangago.zone/read-manga/social_temperature/
King's maker
https://www.mangago.zone/read-manga/king_s_maker/
Black lotus( Dog blood, drama(the kind similar to ones asian aunties watch at home, but bl version))
https://www.mangago.zone/read-manga/black_lotus/
one of my guy mates has asked me to recc him some yaoi (hes straight) so i dont wanna give him anything too intense. ig just ease into it. Any suggestions?