Any time smegma is applied to the upper lip forming a rich, cheesy stache.
I probably should have washed my junk a little before she went down on me... When she was finished, she had a smegmastache that occupied her entire upper lip.
v. to dip one's finger between the foreskin and the shaft of the uncircumcised penis during sex, circling around the head until a bounty of smegma has been collected for distribution onto your partner's upper lip.
your girlfriend told me that you done gave her a smegma stache after not washing your junkhood for a fortnight and shit. that's some seriously tremendous green boner lip action, friend.