I was talking to a troubled student about family problems that she's having, after class as she asked to talk to me confidentially. It was the first time all year that she's opened up to me, and possibly to anyone. In the middle of our conversation, a substitute walked in to return some resources she'd borrowed from me. I asked her if she could please wait a few minutes, but she barged in anyway, said some rude things to me, walked toward the door, turned around, and then made other rude comments before finally leaving. The sub's behavior made the student uncomfortable, and she left. I'm not sure how to handle the situation. Should I let it go or report the sub? I'm leaning towards reporting the sub, but I'd hate to ruin her chances at coming back if I'm overreacting.