When two men (or women) are changing clothes in a locker room with their backs to eachother, and they bend over to
pull down their pants at the same
time by accident. This results in their asses touching eachother. Thus, a
moon landing.
Brad and Billy are getting ready for football practice, and they both happen to
pull down their pants at the same time.
Brad: "Woa dude! What the heck man?"
Billy: "What's wrong with you?"
Brad: "Your ass just touched mine!"
Billy: "Awe come on,
you can't tell me this is your first
moon landing."
Brad: "There's a name for it?"