Front-stabber 

Someone who tells you the truth to your face, instead of talking smack about you behind your back. It could be a friend who loves you, or a jerk who hates you. Chances are, it’s not your mom.

She was a true front-stabber, meaning she didn’t mind spilling the truth, face to face, and then, she twisted that knife just a little.

Front-stabber by Undo_Save? April 4, 2021

frontstabber

One who does you a favor. Antonym of backstabber

Dude you left your keys at my apartment last night. Here you go.
Oh, thanks.
Yeah I also took the favor of carrying your recycles outside.
Wow you're such a frontstabber!
Did that acid wear off yet?

frontstabber by jscales January 10, 2008

Frontstabber

Someone who's up front about putting their knife between your ribs.

He/she was a frontstabber, so having your back turned wasn't the only time to be aware of what he/she was doing.

Frontstabber by Solid Mantis August 6, 2019