Cassidy blinks in mild confusion at Diego's insistence for him to stay away, but ultimately relents with a slow duck of his head and a hand raised in defeat.

"A-alright, mate, alright," he concedes lightly as Diego stalks off. Probably better than him punching more, but still not exactly the best way to end an argument. Cass just lingers at the door, calling after him, "I'll stay away, I swear."

But if Klaus chooses to come back after he's healed? Well, that's his own choice, he's a big boy.