While promoting “Friends With Benefits” in Moscow, a Russian reporter had the gall to ask Justin Timberlake, “why movies” (in lieu of, say, music).

It’s a question everyone has wondered.

A delay in translation kept Timberlake from responding, so his co-star Mila Kunis jumped in to deliver a verbal smackdown in the reporter’s native tongue.

“Why movies? Why not?” Kunis, who moved to California from Ukraine at age 7, testily replied. “What kind of question is that? Why are you here?”

The look on Justin’s face is priceless.