When a girl is giving you head. When your reaching the point of orgasm...tell her a joke or a lymric or anything of a commical nature...something that will make her laugh when your ready to ejaculate. At this point cum will shoot out her nostrils very similar to the way milk does when laughter is enduced.
you when bill cosby gave this girl the milkman...she cracked up when she saw his sweater...which was later stained...he got pissed and threw her out the window.
When a girl is giving you head (she must be on all fours) and you are about to cum, knock her hands out from under her. This will cause the cum to exit via the nostrils, hence the name milkman.
Dude, The Milkman paid a visit to my girl last night, she's still got cum in her nose.