A PL's wife was very suspicious when one day she found a small wooden box hidden in his sock drawer. It contained three golf balls and $2,000 in cash.
She confronted him, and he was so unprepared for her discovery that he simply blurted out the truth. "I'm sorry dear, but I go to strip clubs and every time I get a blowjob from a stripper, I put a golf ball in this box."
She was incredibly pissed off, and started screaming about divorcing him. With much reflection, however, she eventually realized that she had put on a bunch of weight over the years and hadn't been giving him much sex for a very long time. So they talked. She eventually came to the conclusion that three instances of infidelity in a 30 year marriage wasn't really that bad, so she could forgive him.
"But dear," she said, "I've just got one more question: where did the $2000 come from? "
"Oh that's easy," he said. "Every time I got a dozen golf balls the box was full so I sold them."
Wow. I bet that there were two more balls in the box about two seconds later :)