This is a bit of information, nothing to do with this game.
"PARTY POST OFFICE GAME"
The group playing is divided into a group of boys and a group of girls. One group (boys or girls) goes into another space or room, such as a bedroom, which is called "the post office." To play, each person from the stationary group individually visits "the post office"-- once there, they receive a kiss from every member in the room.
Once everyone in the first group has taken a turn, the other group begins sending members to the first room. In this way every member of both groups is guaranteed a kiss from every member of the opposite sex.