Boyfriend’s friends ask me why I date him, why I put up with him

My boyfriend’s friends have asked on multiple occasions without knowing others have asked me why I put up with him what do I see in him that kind of thing. I can’t tell if they are joking but most of the time I think they are serious. My boyfriend himself has asked me before why do I stay with him. His friends hated me before they met me bc they thought I had to be an insane b*tch to date him, they were shocked to see I was actually really put together and nice. I told his one best friends girlfriend about how he acted when meeting my parents and she said “I know you like him, but that’s sorta a red flag”. How do I take that?!?!?! She then went on to day “you have to decide if it’s a deal breaker or not to you”. Ive been dating this guy for 6 months now