A man and a women were married for 40 years. When they first got married
the man said "I am putting a box under the bed. You must promise never
to look in it". 

In all their 40 years of marriage the woman never looked. However on the
afternoon of their 40th anniversary curiosity got the best of her and
she lifted the lid and peeked inside. 

In the box were 3 empty beer  bottles and $1874.25 in small bills. She closed 
the box and put it back  under the bed. Now that she knew what was in the box, 
she was doubly  curious as to why. 

That evening they were out for a special dinner at  their favorite restaurant. 
After dinner the woman could no longer  contain her curiosity and she confessed,
saying: "I am so sorry. For all  these years I kept my promise and never looked. 
However today the  temptation was too much and I gave in. But now I need to 
know why do you  keep the bottles in the box?" 

The man thought for a while and said: "I guess after all these wonderful  years 
you deserve to know the truth: "Whenever I was unfaithful to you I  put an empty 
beer bottle in the box under the bed to remind myself not  to do it again." 

The woman 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
years." 

They hugged and made their peace. A little while later the woman asked
the man: "Why do you have all that money in the box?"

To which the man answered: "Whenever the box filled with empties, I
returned them for the deposit."