Open Question: Is my best friend overreacting, what do you guys think?

We are both 18 years old guys who just graduated high school about 3 1/2 weeks ago, been best friends since pre-school. So about two months ago, I made a comment to a new picture my best friend posted on MySpace saying: "You look chubbier, is it the food from McDonalds?" in a joking manner, with expression faces and such, indicating that I was joking, he makes it so he has to approve the