It's a sex act having a similar name to dirty Sanchez but for the weak hearted. It's when a man and a woman engage in oral sex, then the man takes his penis and rubs it above the girls upper lip leaving his cum like a moustache.

A pick me is a woman that is willing to do anything for male approval. She will embarrass or throw other women under the bus to achieve this goal. The unfortunate thing about a pick me is usually the men they are trying to seek approval from are of poor quality and treat women badly, leaving little real benefit for the pick me.