Duh!?

I was innocently sitting at the dinning room table on my laptop earlier, when a highlight of my week occured:
"Who the hell is this now?" My dad points over my face at my laptop wallpaper.
"Thats Billie...duh!"
"Thats not Billie, is it?"
"Uh yeah. Who else would it be?" Then my mom walks through not in the room to hear the first half
"Really hun, would it be anyone else?" My dad drops his head and puts his arms in the air.
"Im sorry. I dont know what I was thinking."