Boyfriend jealous of Male best friend

My and my boyfriend have been together 2.5 years and have a baby together, we were friends two years before dating. I've had the same male best friend for almost has long as I've known my so. My best friend is always super thoughtful and has been there for me through so much. I have 0 interest in dating him or being with him and my so knows that. For the first year and a half of dating he had no problem with my best friend. I never hang out with my buddy, or text/ call him, but we work together and have an hour- and hour and a half each day together. Whenever me and my boyfriend get in an argument he throws by best friend into it and about how he doesnt want me talking to my friends he thinks my friend is in love with me, and why dont I just date my friend type shit. When we calm down I always ask him if he meant what he said about my friend and if so then I'll push him away a bit. My so says no I was just mad I'm happy you have such a good friend and that type of boyfriend knows my friend has stood up to other men about my relationship and makes sure people know I'm not available. Well last night everything was fine with my boyfriend. I was pet sitting my friends (female friend also from work) Guinea pig and I'm highly allergic to pine which is the bedding. I spent all weekend with hives and having a hard time breathing. I told my boyfriend that I was going to text my Male friend to help me in the morning. No issue. So I text my friend right in front of my boyfriend something like reminding him of my allergy and asked him to get the Guinea pig from my car and bring it to the owner. No issues my friend says of course. My boyfriend got nasty with me later on about why dont I just go be with my Male friend because I want him. We went through the same bullshit argument and it ended with my boyfriend really not caring because he knows my friend is just a friend. This morning my friend came to get the Guinea pig and brought me coffee and a benedryl just in case. Hes legit just a great friend. What do I do? I'm tired of the fighting but then my bf says it's not a big deal and hes happy I have such a great friend.