I once had a job where the safety manager was a woman. At the beginning of me working there, we had to go through all sorts of orientations. She was around my age and pretty cool so the conversation would veer off-topic to personal life stuff. I treated her like any dude I'd talk to out on the floor. I was, at the time, very happily in a relationship with a girl for the last three years. Not long after, every other sentence she uttered was "my boyfriend does that", "yeah, my boyfriend...". Like, at least 10+ "my boyfriends"... It was noticeable and uncomfortable. I had absolutely zero interest in this woman. She was definitely conventionally attractive and I guess she's used to guys hitting on her and was just defensive in that way. I didn't really know how to handle talking to her without addressing it. Which would be very awkward. I basically didn't talk to her during the rest of her time there unless it was work related and strictly professional. As a guy, when someone does that, it leaves you wondering what you did to make them think you were (potentially?) hitting on them. It can suck when someone is cool and you were just chatting and they misunderstand you but what can you do?