In love with my friend

I had a "friends with benefits" situation with a friend of mine many years ago, but he ended it when he got back together with his ex-girlfriend. We remained platonic friends since then, but my feelings for him never really went away. I've been in a relationship with someone else now for 5 years. I love my boyfriend and am really happy with him, but nevertheless, the feelings I have for my friend persist. I feel like I'm betraying my boyfriend by having these feelings, but I don't know how to make them go away!