"I know that you are aware of that, but--" He stops again, looking down at Bumblebee as a hand rests itself on his shoulder. "I don't want to lose you again."

It's hard for Optimus to admit it. Not that he wasn't close to Bumblebee, but that he was showing such weakness openly. He wanted to be strong as he'd always been. But Bumblebee--losing Bumblebee...

He'd be lying if he said that wasn't on the list of biggest fears.