shampainwishes:

Dirty Sanchez is commonly mistaken to be an act where the fecal matter it purposefully smeared onto a partner’s upper lip. The term ‘dirty sanchez’ originated in the porn industry, particularly films involving ass to mouth action. It describes the (originally unintentional, i.e. blooper) act of leaving a fecal matter “moustache” on a partner’s face by taking the penis out of the anus and putting it in the mouth without wiping it off first. The result is that as the penis is thrust between the lips, fecal matter is scraped off and comes to rest on the upper lip in a moustache configuration.