Don was whistling when he arrived home from work. It was Friday and the weekend stretched ahead. He and his wife were going out on the town while the kids stayed home. It was a time to relax and have fun.

Entering the house Marie, his wife, threw a small fly into the ointment.

"Don, Helen can't babysit tonight," she announced.

I am not taking those little monsters to the party with us, was Don's immediate thought. This was followed by the realisation that Marie didn't seem particularly disappointed, only slightly wary. She obviously had more news but was unsure of how he'd take it. He waited.

"I managed to...