Why you never question a drunk

[fibroman]

I was shopping at the local supermarket where I selected:
milk
eggs
orange juice
lettuce
coffee
bacon

I was unloading my items on the conveyor belt to check out, a drunk standing behind me watched as I placed the items in front of the cashier. While the cashier was ringing up the purchases, the drunk calmly stated, 'You must be single.'

I was a bit startled by this proclamation, but I was intrigued by the inebriated gentleman's intuition, since I was indeed single I looked at the six items on the belt and saw nothing particularly unusual about my selections that could have tipped off the drunk to my marital status.

Curiosity getting the better of me, I said: 'Well, you know what, you're absolutely right. But how on earth did you know that?'

The drunk replied, 'Cause you're ugly.