When my wife, Susan, and I decided to tell Tommy and Renee that we were swingers, we knew what the reaction would be. Tommy is our son. He is 27 years old, a little over 6 feet tall and about 225 pounds. Renee is our 25 year old daughter in law. She is a pretty blonde about 5'3" and 125 pounds. "Ewwww." Tommy scowled, crunching his face up like he had just bit into a lemon. "Mom, I don't even want to think about you havin...