拍马屁 (pāi mǎ pì)

The idiom "拍马屁 (pāimǎpì)" literally means "to pat the horse's butt." It originates from the practice of flattering someone by patting their horse, an action that was seen as insincere and excessive. Today, it describes the act of excessive or insincere flattery, often used to gain favor with someone.

For example:

Tā zǒng shì pāi mǎ pì, shì tú huò dé lǎo bǎn de qīng lài.
他总是拍马屁，试图获得老板的青睐。
He always flatters excessively to try to gain the boss's favor.

Source:eChineseLearning