Credit: Kelsey McNeal/ABC Photo: Grey's Anatomy Season 10, Episode 10: Stephanie Edwards, Meredith Grey, and Jo Wilson

Looks like Mer is being aggressive in her treatment of a Steph infection in this week's episode of Grey's Anatomy — and Jerrika is taking to Twitter defend her on-screen persona!

In a promotional image from the episode airing this Thursday, November 21 — Season 10, Episode 10, "Somebody That I Used to Know"Meredith (Ellen Pompeo) seems to be shooing Stephanie (Jerrika Hinton) away.

A Grey's fan with the Twitter handle @coolteacher31 posted the pic to Twitter, writing, "Dr. Grey doesn't look happy with Dr. Edwards."

And Jerrika retweeted that self-proclaimed cool teacher's post and added, "That's what happens when you do the right thing."

It sure looks like Meredith is stopping Stephanie dead in her tracks with a clear "step off" stance — with Jo looking at Steph over Mer's shoulder with a "sorry 'bout it" expression.

As @coolteacher and other Twitter users pointed out, Mer's reasons for being hostile toward Steph are twofold.

For one, Stephanie blabbed to Cristina (Sandra Oh) about Mer's 3D printer in Season 10, Episode 8: "Two Against One." To add insult to injury, she also shut Mer's argument down in the OR with Richard's (James Pickens Jr.) two-challenge rule in the same episode.

Sorry, Stephanie. Normally it's good to take a stand, but it looks like you crossed the wrong attending this time!

Dan Clarendon is an assistant editor at Wetpaint Entertainment. Follow him on Twitter and Google+!