The ACTUAL meaning of negging is not ‘teasing,’ but:

• say/do something to imply you’re not attracted/interested in them
• eithee lowers their self esteem til they’re “at your level,” or
• it supposedly gives them a burning desire to be desired by you, to rise to that challenge

In this sense it can be seen as a toxic extension to the “playing hard to get” concept.

It was pushed by american media and by pickup artists/ later by manosphere influencers