Should u apologize

Liiz

I have been friends with this guess who live in a different state then I do. CT + VA We have this friends with benefits thing going on. Every time he comes to town we end up having sex. But this time he gets a hotel and he brings this girl over. My best friend tells me it his girlfriend. When I ask him he says no that they just friends and his mother invited her over. I believe him. So this happen with him and this girl blah blah blah so goes back home and I go to the hotel. We have sex. A few days later I ask him bout her. He send me a picture of her where she posted a post calling him a fuck boy so I question him about it. He doesn't deny having sex with her. At this point idk know how to feel because I believe it when he told me they were friends. I didn't even think about asking him if they were having sex. So he got really upset because how I reacted. My best friend thinks that I was doing to much asking him questions. Should I apologize.