My mom does that all the time. Every time I chat with her on the phone, she always brings up my bisexuality and asks if my best friend is the girl I'm "dating". I don't know how many times I have to tell her that we're just friends and that I'm still single. I understand that she's trying to be okay with it by talking about it and showing me her respect for it but she treats it like there are only 5 of us in the entire world. It's really annoying.