[NSFW] Their Honeymoon

So,

There is a man and his wife on their honeymoon and he slips a shoebox under the bed before they 'get down to business'.
'Now honey,' The husband says, 'Whatever you do, don't open that box. You must not, under any circumstances, open that box'

The wife thinks this is a strange request, but ignores it and they start enjoying themselves.

21 years on, and her curiosity gets the better of her. So she goes up to their room and finds the shoe box still under the bed. She opens it and finds three beer cans and a wad of money.

She takes the box down to her husband who is watching football and puts it on the coffee table,
"Honey, whats with the box?" She asks him. He sighs,
"Well, since you've waited this long, i'll tell you. Each beer can represents every time I've cheated."
"Ok...3 times in 21 years...I can live with that. But why all the money?"
"Well, thats for every time the box filled up."