Dealing with my roommate. Need help.

I am currently living with one of my friends that I've known forever and his parents. His parents are the nicest people and they've been so supportive of me over the past few months. The problem is that my friend has had this weird, almost obsession with me since about kindergarten (we both just graduated high school). Any time I date anyone, he stops talking to me or starts being rude. It's gotten bad recently because I'm coming up on a year with my boyfriend. My friend won't talk to me, and now my boyfriend isn't allowed over anymore. When I asked his mom why, she told me it's because it stresses him out and she doesn't want him to be upset. It's their house so I'm just going along with it. But I feel like being an adult now, he should learn to deal with me not liking him, even though he loves me. I've always been supportive of him dating any girl he wants, but the second my boyfriend is brought up, he says that's gross and he won't look at me.