An unusual sex act developed in the late seventies. It involves a man wearing a white sheet to make him resemble a ghost. He then has sex with a woman. Ideally, the sex will take place in an actual post office. As he climaxes, he cums into an envelope. He takes this envelope and and mails it to his sex partner's mother.
Mary and I did some freaky stuff last night, we even tried a Haunted Post Office.