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2.
The act of slapping one in the mouth with a penis after the mouth has been filled with ejaculate.
Randy's leg looks like somebody just gave it a milky slap.
by Wes February 14, 2005
 
1.
When one slaps his ejaculated penis in another's face smearing cum everywhere.
Dude, I totally gave your sister a sloppy milky slap last night.
by Ryan Huie February 13, 2005