A man walks into a cafe and orders a cocktail. He takes his first sip and sets it down.

While he is looking around the cafe, a hot girl grabs the drink pours it on his head, and stabs him with the umbrella.

This man asks the barman, “Who is that girl?”.

The barman replies “She’s the piano player’s girlfriend”.

The man walks over to the piano player and says, “Do you know your girlfriend poured a drink on me and stabbed me in the back?”

The pianist replies “No, but if you hum it, I’ll play it.”