When John and Martha first got married, John said, "I am putting a box under our bed. You must promise never to look in it."
In all their 30 years of marriage, Martha never looked.
However, on the afternoon of their 30th anniversary, curiosity got the better of her and she lifted the lid and peeked inside.
In the box there were three empty beer cans and $1,852.38 in cash.
After dinner, Martha could no longer contain her guilt and she confessed, saying, "John, I am so sorry. For all these years I kept my promise and never looked in the box under our bed. However, today the temptation was too much and I gave in.
"But now I need to know. Why do you keep those empty beer cans in the box?"
John thought for a while and said, "I guess that after all these years you deserve to know the truth. Whenever I was unfaithful to you, I put an empty beer can in the box under the bed to remind myself not to do it again."
Martha was shocked, but said, "I am very disappointed and saddened, but I guess after all those years away from home on the road, temptation does happen and I guess that 3 times is not that bad considering the number of years we've been together."
They hugged and made their peace.
A little while later, Martha asked John, "So why do you have all that money in the box?"
John answered, "Well, whenever the box filled up with empty cans, I took them to the recycling center and redeemed them for cash."