Try with these or check a big boob bl list, this is how I found these
https://www.mangago.zone/read-manga/momichupa_oppabu_fever_time/
https://www.mangago.zone/read-manga/momichupa_oppabu_osu_time/
i found it like right after this and i definitely described it wrong but i found it on a big tits list ty tho(￣∇￣")
if u want it js look up usagi chan on here
it's the first thing on page 2
Basically it's a gay seme who's a virgin and he's like fuck nah i'm tired of this virgin shit so he calls over the uke who's "straight" and buff and he works at a call boy shop or something i can't remember but anyway one scene i remember is uke using his chest to rub againsts semes dick and the seme is like holy shit is this what he thinks gay ppl do this is hot and then blahblah blah they fall in love help me find ts yo