Oh! I have a somewhat amusing anecdote!
My friend is a paramedic, and like, one of his friends on the force (team?) has sensitivity issues in that he's a 45 second man. So, what does he do? He takes some topical lidocain (sp?) from the rig. He gets home and wants a blow job. So like, before he sticks it in his girlfriend's mouth, he put some on without telling her. She starts sucking, and the left side of her face goes numb. She thought she was having a stroke! And he STILL refused to tell her! So like, they get to the hospital, and he had to confess to the doc.