There's a guy and a girl and they want to have sex. So, they go to the girl's house and before entering her room, the girl stops and says, "My little sister sleeps on the bottom bunk of our bed and I do not want her to know what we are doing. So when I say, 'Baloney,' it means push harder, and when I say, 'Pastrami,' it means push softer."
With this, the two get onto the top bunk and start having sex. First, the girl moans, "Baloney! Baloney! Baloney!" Then, she shouts, "Pastrami! Pastrami! Pastrami!" Then, she changes back to, "Baloney! Baloney! Baloney!"
Finally, the girl's sister yells, "Will you guys quit making sandwiches up there? You're getting mayonnaise all over me!"