You were backhanded by the enraged villain. Their anger was terrifying. Vito glared down at you and said,

"How fucking dare you let him see someone that belongs to me. You do know that you belong to me, right? If you don't I will gladly remind you. Understood!?"

He said as he waited for your response. You had no clear expression on your face, you don't really understand what you did by talking to your friend, but Vito didn't like how that 'friend' was staring at you.