James immediately did as Teddy said and stepped behind him, though he felt guilty for putting his honourary brother between himself and the other wizard who was clearly intent on him. He briefly considered claiming to be James Lupin or James Dobbs or some other varient thereof, but he doubted that that would work at this point.
Another possibility crossed his mind. He knew it was ludicrous, that Teddy would never let him do it, but he whispered it anyway. "Teddy, maybe I should just go with him. He's going to attack you first, I don't want you to get hurt." Even as he said it, though, he was already expecting the negative response.