50 years of marriage

An old couple, 50 years of marriage, are sitting as usual side by side on a park bench. Her, feeding the pigeons, him, reading the newspaper.

Suddenly, she stops, looks at her husband gravely, slaps him hard and says: “This is for 50 years of bad sex.”

Surprised and confused, he stands still a minute, and finally slaps his wife back saying: “This is for you knowing the difference!”