So I’m super attracted to my roommate and his girlfriend. I know he’s not into me but I’m pretty sure his girlfriend is, I just have no idea how to even begin approaching them about the possibility of a v or something? How would i even go about that?

Has the girlfriend made any indication of wanting other partners? Do you have any idea whether this couple is open to a v arrangement? If not, my advice would be to leave this alone. The vast majority of the population hasn’t been exposed to the idea of healthy nonmonogamy, and approaching your roommate about a desire to sleep with his girlfriend is inappropriate in almost all circumstances.

Not all things can be solved with the perfect communication style. There are plenty of people for whom absolutely nothing you could say would come off as approaching them about the potential for a healthy, open polyamorous grouping. My recommendation is to bring up the idea of poly/open relationships with your roommate in a neutral way - as in, you read an article about it and wonder what he thinks. If his reaction is anything but enthusiastic interest, I’d suggest you drop this. If you want to find yourself in a V or other poly group, there are plenty of poly communities full of couples and other folks looking for partners.