Two brother are sharing a bunk. The older brother and his girlfriend are on the top bunk having sex. So when the girls whats it harder she'll yell tomato and the brother we'll yell lettuce when it feels good. The older brother and his girlfriends keep shouting lettuce tomato over and over. So the little brother is underneath the bunk and hears them and he says "Stop making sandwiches because I keep tasting the mayo."