Help!! Crush while in a relationship?!

So, I'm currently a senior in college and there's a guy in the same major as me (we'll call him Sam). We haven't talked much throughout the past 4 years except for the occasional class we share. We're not exactly in the same clique and he's pretty shy so yeah...he's a very mysterious character to me, but the things that I do know about him, I don't share with (such as music taste, some longterm life goals). But overall, he's intelligent and charming, in an awkward shy guy type of way. 

Anyways, I've had a crush on him long before I even met my boyfriend, but I'm also madly attracted to my bf. My crush, I concluded, is purely superficial, but I still can't help but feel guilty whenever I'm around him. My boyfriend knows that I like him and knows I wouldn't do anything, so I just need tips on how to get over this. 

Thank you so much!