Boyfriend seem rude and won't talk to a mutual friend. Should it concern me?

It started with I think the promise to visit that never happened over the years that he went abroad to study. My female friend I think was just waiting till I moved in with him so that she didn't have to be concerned about the sleeping arrangement since he only had the one bed. I think he is mad because he thinks SHE thinks he can't be trusted and kept giving him lame excuses why she couldn't visit. Yesterday, she skyped with me and wanted to talk to him too but he couldn't be bothered and even seemed to me as if he was deliberately being rude. I was preplexed because earlier when she called he asked why didn't she call his phone instead. I just said because she was my friend too and maybe she just wanted to call my phone? I was a bit annoyed by his behavior and asked him why didn't he want to chat when earlier he gave an indication as if he wanted to. He just didn't elaborate other than say he couldn't be bothered with her.

Should I somehow patch things up? Things are going awkward. Is it just their problem and I should just leave it as that? Is this mature guy behavior? Not sure where to go from here other than feel annoyed at the situation.