during the act of a blowjob when you cum you pull out and push her head under your ass. you then proceed to shit on her head creating a mud pie on her head

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.