Some one who doesn't take sides between two groups, such as racists and anti-racists, and freely associates with the two.
Antifa 1: "Oi! I hear Davey has been hangin' out with a bunch of fascists!"
Antifa 2 "I don't want to be his friend anymore. The fucking fencewalker!"
A person that acts like something around a certain group of people then goes and, acts different with another group of people.
She's all "punk" around us but, when she gets around the preps she acts like them.