<human>: Can you summarize the given text in a few sentences?

**A little background:** My boyfriend and I have been together for 9 months now and we just got back from a trip with his family a few days ago. I love him very much--he's a great guy who is extremely caring, honest, and loving. Not only do I love him but I respect him. That's why this is such a big deal to me--he's a really stand-up guy and I feel like I may have lost some of that respect. The honeymoon phase of the relationship is starting to ware off as I'm getting to know him better and better (especially whenever we go on trips together). I understand and accept the fact that we all have flaws and I've accepted his since I love him. 

Here's the thing about him: he has a bit of an issue with his ego--because of this, he's the type of person who loves arguments and always has to be right. This hasn't been a big issue with us since he's a lot more conscious of it around me, but I've noticed it with his interactions with other people. 

He's usually very respectful with his mom. He loves her and is respectful and affectionate with her. But when we were packing, he said something to her that made me feel extremely uncomfortable. I didn't hear everything, but I could tell she was pestering him about something since we were in a rush to leave and he lost his cool and told her, "go fuck yourself." The remark, accompanied by her nonchalant response made me *extremely* uncomfortable. 

I always hear people saying that if a guy openly disrespects his mother he won't have a problem doing the same to his SO. So far, he's been very respectful and caring in the way he treats me, but hearing that left a bad feeling in my stomach. I couldn't stop thinking about it the whole day. 

So what would you do in my situation? Would you talk to him about it? We're usually good with communication, but I don't know if I should bring it up or how I should feel about it. Am I overthinking it? Tell me what you think.
<bot>: SO told his mom "go fuck yourself" and I can't stop thinking about how uncomfortable it made me. Not sure if I should confront him or not