For the record, I'm 18 and male. Was talking to my mother and her friend and I was about to leave, and the friend said "Why are you so happy to go? are girls going to be there?" And then my mother replied "Why would he care if girls are there?" Kinda caught me off guard, am I looking too much into it or does she know?
Could mean anything. I don't know. Seems pretty casual. I don't think so. But she might. Did she say anything after that?
She may have just had a "feeling" for a while. As far as knowing, maybe or maybe not. But it's something that parents pick up on even if they haven't seen or found any evidence... They just get the vibes from living with you for a long time.. So it is unsure if she just "feels" or has found out about it.