red!

Aunt Flo came and gave me a surprise attack during microbe experiment today.  Guess what happened to my white coat.

Goe (a male classmate): Let's go get our coat sterilized.
Me: Hm...
Goe: Let's go.
Me: I'll go after you.
Goe: Huh?  What's up?
Yu (a female classmate who knows what's going on under my butt): Leave her alone, Goe.  Let's go.
Goe: What is it?  I'm not going until you tell me.
Me: ...I think I have something on my coat.
Goe: What?
Me: *looks behind at my own butt*
Goe: Oh... THAT...
Me: What, you see it?
Goe: No, you're fine.  Uh... I guess I'll go.

The girls helped me out of trouble after that.  It was so embarrassing...