While your sex partner is positioned doggy-style you put your thumb up her/his ass and when he/she turns around you draw a line just above her/his lip with your thumb.
PS.
If a thick line is left it may also be referred to as "giving a Hitler"
i totally gave that chick a Spanish-moustache last night. Then she kicked me in the balls.
by Spanklord August 28, 2008
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