Mila Kunis came to co-star Justin Timberlake's defense at a Moscow press junket for Friends With Benefits -- and she did it in Russian!

The reporter asked why Timberlake is focusing on movies instead of music, and Kunis pounced all over her! She said:

    "Why movies? Why not? What kind of question is that? Why are you here?"

Ouch! Justin is adorable -- he's got headphones on to hear the translations, and jokes that Kunis is his "bodyguard." Watch it all in the video above!

So why does Kunis speak fluent Russian? Find out after the jump!