How old am I?

Gavin started summer school this week. The first day he came home I was quizzing him about school. Did he recognize any old friends? What did they learn? Who was his teacher? We also had this little exchange....

Me: "So is your new teacher young or old?"

Gavin: "She's really young."

Me: "My age or younger?"

Gavin: "About your age."

Me: "So, you think I'm really young? Thank you."

Gavin: "Nevermind, I guess she's old. You are old. Anyway.... she is nice."