I think I have feelings for my boyfriends best friend

Ok so me and my boyfriend have been together for a little over two years and I love him to death. But for the past two weeks I've been having dreams about one of his best friends and when I say dreams I don't mean normal dreams where he just appears in it I mean dreams where we literally make out and have sex the whole time. Me and my boyfriend have been with his friend all day and we went to the shop that his friends jeep is at and the whole way there I was sitting in between them and our legs were touching and it literally felt like my whole body was on fire because of him. Anyways do y'all have any advice that would be helpful?