I’m in a relationship but I think I have feelings for someone else

I’m in a serious relationship with my boyfriend. We both seem to want this to be a very long term thing. We love each other and for the most part we’re usually pretty happy together. Of course we have problems as every couple does, but we usually get over them. But here’s the thing: We have all of the same friends, and we tend to spend a lot of time with these friends, and recently I think that I’ve started to have feelings for one of our friends. Is it even possible to love someone but also have feelings for someone else? I feel incredibly guilty about it but at the same time there’s not much I can do about the way that i feel. At least I haven’t acted on it, and I never would, I would never consider cheating on my boyfriend. But I don’t know what to do, because theres no way this can be healthy for our relationship. Any advice?