It's one where this guy is in love with his best friend, then he lets his bf have sex with his girlfriend in his apartment. While that's happening he has sex with his neighbor...
Ring any bells?
٩(๑❛ᴗ❛๑)۶
Indeed, here:
http://www.mangago.me/read-manga/kocchi_muite_ai/
Have fun, love this manga(づ ̄ ³ ̄)づ
the seme is a cooking class instructor and uke goes to his class for some reason or lived next to him can't remember anyway at the end really cute funny scene where they're doing the nasty in the kitchen and the seme sticks a carrot in the guy's butt (sorry but that's the only part I can remember haha (⊙…⊙ )⁄(⁄ ⁄·⁄ω⁄·⁄ ⁄)⁄
maybe?
http://www.mangago.me/read-manga/koisuru_omocha/mf/v02/c007/2/
though it`s the uke putting in the carrot here - but the seme sees him and "helps" (๑•ㅂ•)و✧
Or maybe this
http://www.mangago.me/read-manga/kimi_no_karada_ni_koishiteru/ ch.4
https://myreadingmanga.info/abarenbo-honey-jp/