My wife left me... And I don't  understand.                        

After the last child was born, she told me we had to cut back on expenses

 I had to give up drinking beer.
I was not a big drinker, maybe a 12-pack on weekends.
Anyway, I gave it up but I noticed the other day when she came home from grocery shopping, the receipt included $45 for makeup.

I said, "Wait a minute I've given up beer and you haven't given up anything!"

She said, "I buy that makeup for you, so I can look pretty for you."

I told her, "Hell, that's what the beer was for!"

I don't think she'll be back.