This happened to me recently.
I have a friend that I’ve known for 3 or so years. As far as I know he’s a really good guy but I don’t talk to him often, i only talk to him in class or other occasions.
Last week he came to school really late(about 2 hours before school ended). As I was heading to the bathroom I see him getting out of a his mom’s car and since the bathroom is pretty close to the parking lot, I go say hi and we chat for a bit.
We end the conversation and I go to the bathroom and do what I need to do. When I walk out of the bathroom his mom is right there. She says hi and tells me she needs to talk to me about her son.
I respond with something along the lines of “sure, what is it?” But she says she is in a bit of a hurry so she asks for my number so we can talk later. I give her my number, say goodbye and go back to my class.