If there is one word that destroys a marriage it is "What?".
It's usually followed by, "I told you that yesterday, didn't you hear me?"
"If I heard you, would I be asking? The washing machine was on."
"What?"
"I said, I probably didn't hear you because the washing machine was on!!"
"Wait a minute. I'll be in there. You always wait till I'm at the back of the house! Now what was it you said? I couldn't hear you for the washing machine!"