a person who whacks off into a mailbox

A tall wooden platform with a ramp for mountian bikers and BMXers to roll in from to send it on some sick trails and jumps.

When someone corners another person and kisses them with no way for the other person to escape

the act of placing an explicit picture into someone's mailbox covered with white soap which is to represent cum

v.

Typically, mail boxing requires three people; two being 'together' and the third man being .. unfortunate. In on it Person A will either walk up to Unsuspecting Civilian, and perhaps engage them conversation. Meanwhile, in on it Person B will creeper-sneak behind Unsuspecting Civilian and go on all fours behind them. Person A will then shove Unsuspecting Civilian, who falls backward in a confused and, hopefully amused heap while Person B gets up unaffected. To be a successful mail box team requires time and practice, and it can be beneficial to stick with one partner (especially for the more difficult endeavors). If you find yourself an Unsuspecting Civilian, you should be happy to know that you are worth mail boxing and it's all in good fun (or is it?)

Mail boxing tends to involve three people, but can include many more if a mail box war breaks out. It is a great way to pass gym classes with subs or introduce new members to your crew or track team. (No, it's not hazing!) Such should be done in grassy areas or padded mats; avoid dangerous objects such as concrete and knives. >.>

Inviting target for heaving melons. Melons may include paradise melons, watermelons, or "gallon" melons. Quite satisfying when contact is made. Points given for damage done. One point for contact, two for dent, three for knocking it sideways, four for knocking it completely of post, or schfifty-five points for taking out the pole and the box.
(That's a record that's only been done once)

Mailbox (n.) - The anus. Often reffered to in a sexual sense.

See chocolate starfish