The red mech stopped and stared down at Rung, eyes flaring. Knock Out's usual demeanor, laid back and teasing, was completely gone. If Rung were paying attention he could have noticed the tension and anger rise in the air. There was a flash of red and white and the next second Knock Out's claws were closing around Rung's neck, not enough to cause high damage but enough to cut the energon flux, and enough to interfere with his vocalizer.

"Words are nothing, Rung. I know my kind, we don't take things lightly and we don't waste time or give second opportunities. Do you really want to know how painful is physical harm? If I decided to kill you know, who'd stop me? This is how Decepticons show dislike for a relationship because emotions are a weakness that should be eradicated. Tarn is from your world, you should know better."

Knock Out's voice was a low growl but he finally let Rung go, none too delicately.