Montgomery turned slowly to Rodolphus, eyes flashing. He evidently hadn't noticed Bellatrix was definitely not herself, and Monty was feeling too woozy to get too irritated by it. He was facepalming plenty on the inside, though.
"Rodolphus, look at your wife again," he said slowly, deliberately, before turning back to the Dark Lord. "Forgive him, my Lord, at least he arrived promptly."