Help me find this pls TT

Full-color bl where the seme has a brother who's tough on him because he's not as assertive. The brother has a lot of tattoos and at some point makes the seme get tattoos too (on his neck I think?) Both the seme and his brother have black hair. I think the seme is in a group project with the uke (?) and in their group there's this scrawny nerd who goes to the seme's apartment at some point and meets the brother and he unintentionally says something that can be taken as homophobic. The brother gets upset so after that the nerd educates himself on queer stuff and wears a bunch of rainbow stuff to prove that he isn't homophobic. The nerd ends up hanging out with the brother a lot after that.