Magic Bitter
He says "Magic Bitter".
She thinks that he's a bit of a nutter, so she walks around the bar for a bit. After realising that there is no one else worth talking to, she goes back to the man sitting at the bar.
She says, "That isn't really Magic Bitter, is it?"
He says, "Yes I'll show you." So he takes a gulp of the bitter, jumps out of the window, flies around the building 3 times, and comes back into the window.
She can't believe it. She says to him. "I bet you can't do that again."
So he takes another gulp of the bitter, flies around the building 3 times, and comes back into the window.
She is amazed. She says that she wants a Magic Bitter.
So the bloke says to the bartender, "Give her a pint of what I am drinking".
She gets her pint, takes a gulp, jumps out of the window, plummets 30 stories, breaks every bone in her body and dies.
The bartender looks up at the bloke and says, "Superman, I've decided you're really not very nice when you're drunk".