What would you do?

I was listening to the radio today, and one of the shows I listen to is "Phone Tap", well if you don't know what "Phone Tap" is here is a brief description: Someone calls a relative, friend or SO with some bogus news about themselves. This was today's "Phone Tap"
A girl , who is away at college, calls her mother and tells her that she has broken up with her long time boyfriend. And her mom is clearly sad for her daughter, and her mother is questioning what happened. Her daughter tells her there was someone else. She then tells her mother that it's her professor. And she want's to bring her professor down to meet her family and she really likes her professor. Her mother starts yelling at her telling her no way is her professor coming down. The daughter tells her mother that the professor is going to call her later and talk to her because she is excited about going. Well she hangs up the phone. Then the radio host calls the mother acting like the professor. The radio host is female. The mother starts flipping out on the said professor. She ends up hanging up & the daughter calls her back and is like OH MY GOD MOM WHAT DID YOU DO! SHE IS SO HURT I CAN'T BELIEVE YOU! etc. Then in the middle of the conversation both chime in saying she had just been phone tapped on such & such radio show....

Now, what would you do if that situation arose with you & your child. Not the phone tap part, but that your child was seeing their professor and that professor turned out to be the same sex as your child? What would you do?