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.

His story:

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, WERENT YOU???!!!