Should I give up my good friend to save my relationship?

So I've known this guy Sammy for 5 or 6 years we know eachother because we both went to boxing together-we lost touch for like a year or two. So okay the problem is that I share a plan with my boyfriend of two years (on and off) and he sees that I talk to sammy on the phone for hours around the times of 8-12 pm and hes telling me he thinks im cheating on him but Im not sammys a really good friend-we talk about the dumbest stuff and its nothing more-should I give up my good friend to save my relationship?