Dedicated to all married scientists:
There was this physicist who was in the habit of getting home quite late. One time, he came home at 2:30 a.m. with a torn shirt, lipstick on his collar, hair messed up, and generally looking like hell. His wife caught him coming in the door and demanded to know why he came home so late.
"Well, after I quit work for the day, a few friends and I went out to the bar for a few drinks. We met up with some rather good-looking young women, and started to drink to excess; things just kept happening, as you can well see. I sobered up enough to note how late it was, so I rushed home."
She said, "YOU LIAR!! YOU WERE IN THE LAB AGAIN, WEREN'T YOU???!!!"