Yeah, I worked in higher ed for a long time. And part of what I did was support victims of sexual assault on campus. And you know what most of those victims of sexual assault had in common? The people who victimized them were associated with frats.

Frats are SEVERELY outdated organizations that do nothing but provide a protective shield for toxic masculinity. They've shown, repeatedly, that they're not actually interested in reforming that purpose. They should have no place on the modern campus. You're involved in a very good, worthwhile, and overdue struggle, and I wish you success. (And if you haven't read it already you may appreciate the classic fraternity ethnography, "Fraternity Gang Rape: Sex, Brotherhood, and Privilege On Campus* by Peggy Reeves Sanday.)

Anyway, that being said, your boyfriend is telling you in so many words: "me having fun with my bros is more important than the victimization of countless women as well as young men, I would rather continue being associated with a frat then prioritize those victims, and I'm unable and unwilling to seek other forms of social interaction." Dump the whole man.