This is the same Roommate i had a crush on but not anymore because he's a ****ed up individual

so he's been dating this guy in his 30's (

) for like two years now. Towards the beginning of their relationship. The 30 year old guy cheated on my roommate because my roommate goes to college 2 hours away from the 30 year old guy and they rarely see each other. Saying he has needs and my roommate isn't around to fulfill them.
ANYWAYS. Long story short my roommate forgave him and they tried a open relationship for a while. Oh yeah, my roommate is on grindr too

he says he's looking for "friends" chile..... If you're looking for friends why haven''t you told your bf your up there?

Not to mention he talks about how hot guys on campus are and how he wants to hook up with them in a joking way but still. ANYWAYS his 30 year old bf is going away for 3 weeks for his job and they basically worked out a agreement that my roommate can hookup because "he has needs"
MIND YOU. The 30 year old boyfriend CONSTANTLY tells my roommate how he wants to marry him and how they want to be together after college and how my roommates the best thing that's happen to him. How do you go from talking about being married to saying your okay with being in a open relationship?

like, do you realize you can't be doing this stuff if you wanna get married. Anyways, he's always asking me for advice on this situation but i've always held my tongue because i don't wanna scalp him, because i believe in loyalty. IMO, it seems like their relationship is VERY dependent on sex. The fact that you have to propose a open relationship because you can't keep your dick in your pants for 3 weeks

when not that long ago you were talking about getting married. Like ya'll mother****ers just hooked up last weekend.

Atrl what do you think of this messy situation and what advice should i give him. I honestly don't wanna be involved in this ********.