The girl had guts, Marcel had to give her that. However, Arianna just crossed a line she shouldn't, no one threatens his people in front of him. It hints at his incompetence. And he hated showing weakness.
It wasn't enough that his men didn't have a good view of her, now they would think the only reason he kept her around was to scratch his itch. If only they knew she hadn't gotten close to an inch of scratching it.
His jaw clenched at her request, get her out of here? Was she kidding him? Hand her on a platter of gold to Elijah? That was over his dead body. That was never happening, but he wouldn't tell her that. She needed to be taught a lesson, this time.
Arianna knew Marcel was not going to grant her that but she was not giving him a choice. So it wasn't surprising when he said, "And what makes you think I care about his life?"