Something Happened Between Him And His Female Friend And He Won't Tell Me

My boyfriend and I recently had a baby. A lot during my pregnancy his female bestie was calling him over for stupid stuff and then starting a fight with him. He said it all started when she started dating this asshole, but idk. They've been friends since pre-k and it did seem weird they were fighting so much. Today he put the baby down for a nap and she texted him saying she needed him for an emergency. He asked if he could go. I was annoyed but I was annoyed but I said yes. He was gone for TWO hours. When he came back he was pissed. When I asked what happened he just yelled "Don't want to talk about it! Fuck Ashley!" I had never heard him talk about like that. I asked if they are still friends and he said " I dont fucking know! I'm not talking talking to her anymore for a while!" Maybe I'm just making it about me, but maybe she came onto him and that pissed him off... idk. I asked what took him two hours and he just said "Dealing with her stupid petty bullshit!" I want to know what happened but he seems really heated. What would you do?