It does not matter how you do it. It's a Fecal Mustache.

NO, a Dirty Sanchez is performed when a male fingers a female's ass and wipes the reminants on the female's upper lip. What you referred to below, when a male inserts his penis in a female's ass then transfers the fecal matter from his penis to the female's upper lip is the Dirty Rodruigez, the first cousin of the Dirty Sanchez. Don't feel bad though, they are commonly confused.

after having anal sex, the man pulls out his penis and wipes it across his partners lip, forming an authentic looking mexican moustache.

It is when you rub shit across your upper lip.

When two people are having anal sex and the man takes out his penis and rubs it on the women's lips forming a mexican mustache/moustache. (The growth of hair between the nose and mouth.)

The real dirty sanchez is when after lovingly cuming in your girl's ass you insert your finger in her pooper and remove cum mix with poop and place it carefully on the upper lip of your loved 1 looking like a well drawn mexican mustache, also known as a "DIRTY PIER" in europe for the resemblance to a french mustache "Pier" and cause they stink, but; almost always welcome when is tastily done.

As defined by Kelly Osbourne on the Howard Stern Show, who is an authority on vulgarity coming from the Osbourne family...Dirty Sanchez is a non-sexual practical joke where the offender inserts their index finger into their vagina or butthole then swipes it across the victims upper lip.