This may confuse you a bit, make you wonder, "Who in their right mind would lick someone's elbow?" I agree that that is a good question, and often ask myself that. That doesn't stop me from participating in the increasingly popular (amongst, like, 6 kids) sport of Elbow Licking. Let me explain.
First, pick a target. A friend of a friend is a fantastic choice, because that friend can distract the target.
Carefully approach the unsuspecting victim with slyness like that of a ninja's.
Lick them quick, then turn away.
If done with precision, they shouldn't feel a thing. Until they figure out what is going on and try to wipe off the spit with their hand.
It may seem rather disgusting at first, but after some practice, licking elbows can become a wholesome recreational activity. You don't truly know a person until you know the taste of their elbow.