It is when you have anal sex with a girl without a condom on and then after you have all the anal juices on your penis and ball sack, you then take it out and stamp (mushroom stamp) right on her forhead but with all the anal juices on her head.
1. Last night yo i gave this girl Jen a mean mexican postage
2. She wanted to have anal last night and i ended up giving her a mexican postage!
by Muffjack2 December 4, 2006
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