frenemesis 

A person with whom you have a long-standing or close relationship, but who is the ultimate frenemy. An arch-rival who pretends to be your good friend, while undermining you behind your back.

She's not just a frenemy, she's my frenemesis.

frenemesis by nodramamama November 11, 2010

frenimies 

A "friend" who really doesn't like you, nor you like she, yet you are drawn togther by some sick dramatic bond.

Hey, there are cards tonight at the frenimies' house. Let's go get dissed.

frenimies by coctailblonde December 24, 2007

Frenimies 

Two people that used to be very close. Then turned into enemies. That is why people call them Frenimies.

We used to be friends but now we are Frenimies.

Frenimies by Frenimies November 29, 2015

frenemesister

That female at work that is sometimes friendly, sometimes your nemesis, sometimes you want to strangle in a sibling kind of way.

That damn frenemesister - yesterday she brought in brownies and today she's in my office talking about office style & credenzas - I don't know whether to strangle, hug, or defenstrate her.

frenemesister by PabloNachos82 January 22, 2021