Ex-Wife…Brilliant continuation in the first comment 
A man and his wife are at a restaurant, and the husband keeps staring at an old drunken lady swigging her gin at a nearby table.
His wife asks, “Do you know her?”
“Yes,” sighs the husband.
“She’s my ex-wife.
She took to drinking right after we divorced seven years ago, and I hear she hasn’t been sober since.”
“My God!” says the wife.
“Who would think a person could go on celebrating that long?”