Days with Letter R

The newlyweds were suffering from exhaustion and after an examination, their doctor advised, "It's not unusual for young people to overdo things during the first weeks of marriage. What you both need is rest. For the next month I want you to limit your sex life to those days of the week with an "r" in them. That is, Thursday, Friday and Saturday."

Since the end of the week was approaching the newlyweds had no immediate difficulty following the medico's orders. But on the first night of scheduled rest the young bride found herself eager as a beaver. Hubby fell asleep, but she tossed and turned and finally nudged her spouse into partial wakefulness.

Expecting daylight, and confused with the darkness, he asked, "What day is it honey?"
She looks at him with a gleam in her eyes and says, "Mondray."