Truth Be Told

Overheard on the way home from piano lessons...
Mom:  "It has been a long week.  I'm glad it's Friday because I'm tired."
Brunette Twin:  "Why are you tired?  It's not like you do anything."
Mom:  "Really?"
Brunette Twin:  "All you do is sit at the computer all the time."
Mom:  "Who cleans?  Who cooks?  Who takes you to school?  Who walks your dog?"
Brunette Twin:  "Dad."
Mom:  "Don't I do any of it?"
Brunette Twin:  "Only when Dad's not around."