A man opens the door for his mother-in-law and declares

A man opens the door for his mother-in-law and declares, "oh, long time, no see! this is a surprise. how long will you be staying with us, this time, then?"

The mother-in-law, trying to be polite, jokingly replies with a big grin, "until you get sick of me."

"oh, really? you won't even stay for a cup of coffee?"