Friends

The classic oldie:

Man comes home, finds his wife with his friend in bed. He shoots his friend and kills him.

Wife says: "If you behave like this, you will lose ALL your friends."

The Scottish version:

Angus McKenzie comes home and finds his wife in bed with his friend. He shoots his wife.

Later, at the pub, his friends ask him why he did that.

Angus: "I can budget one bullet, but I got a lot more friends than I want to buy bullets for!"