Having dreams about the wrong person!? Help!?

Well, I have been with my current boyfriend for 3 1/2 months now. I am very much so in love with him and he knows that. We have a very open and healthy relationship, I couldn't be an happier. Though lately I have been having sexual dreams about my ex. They started small and now there a lot more.. well descriptive and much more intimate. Can somebody please tell me if this means anything or if it's nothing at all. Thanks <3