Jake,
I remember you saying you were in an exclusive relationship with a girl. If this is the same situation, then maybe I can be of some help.
If all you have is physical attraction for her, then maybe she isn't someone you want to be exclusive with in the first place. If both of you are down for some casual sex or a FWB relationship, by all means continue. But if you aren't attracted to her mentally, then I feel like the relationship is/may be doomed. You won't enjoy spending time with her as much as you would if you did find her mentally attractive. Maybe this is why Chase said he doesn't date girls who party and drink, and that they need to have a master's degree (or working on it). It's very possible it is because these girls (the majority at least) have certain character traits that he finds attractive, and that is why he is more willing to be exclusive with them. So everyone should have higher standards for exclusive long-term relationships than standards for hookups.
If you want a ONS, casual sex, or a FWB, then it's not as important to be mentally attracted to the girl, because the relationship is really purely sexual and only about sex. But when you are a couple, I feel the mental aspect has a much greater part in the relationship, because there is always more to a boyfriend-girlfriend relationship than just sex. Sex can and should and will be a big part in a relationship, but if you spend a lot of time with her doing other things, mental attraction will be more and more important.
In your situation, if you really aren't mentally attracted to her much at all, then I think you might want to break it off. Unless you think you can keep her as a FWB and both of you are okay with that (might be hard downgrading her to FWB from a GF role though), I think you should be honest with her about it. Might depend a bit on how long the relationship has been going on and how long you have know her, but I don't think it is fair to either of you to continue on in a relationship in which you aren't feeling it.
If I missed something, or it's the wrong situation, or you have thoughts/questions/responses to my post, let me know.
-Pato
