A phrase instructing the subject to rest his/her forehead on a specified object (such as a table) so that the subject is bent over and easily accessible for doggy-style sexual intercourse.

This phrase is used while slapping the object that the forehead should be placed on with your fingertips, similar to the way the phrase "knock on wood" requires knocking a table.
So you want a good grade on this test, Nancy? *taps the desk* Time to place your forehead.
by Chode Sandwich May 6, 2005
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