The one about morning glory...

A young son woke his father up one morning. While the father was getting out of bed, he realized he had a "morning erection".

In an effort to hide it, he dropped down to his hands and knees and pretended to look under bed for something.

His son asks, "What you looking for Dad?"

The father says, "I thought I saw the cat run under the bed."

His son asks, "What are you gonna do, Dad? Screw it?"