I wouldn't worry about it that much. I've called lots of guys "she's" before and lots of girls "he's" before just by slipping and being excited about what i was talking about. When I go out with my family in public places, my dad still gets pronouns wrong most of the time, and people just think he made a mistake or they think they heard him wrong. If he refers to you as she, dont respond to him, and pretend you didnt even know he was referring to you.