There was a serious conflict of interest in the aftermath of Ira stepping forward to defend Bones, despite the fact that he didn't, initially, think that Fox was going to harm her. Ira's eyes narrowed when Fox snarled at him to never talk to her that way again, but she had stopped being his Alpha a long time ago and he didn't have to do anything she told him. Not that he would have listened before, either. The only woman he had listened to was deceased now, though he was becoming better at listening to Bones, driven only by similar reasons: respect and the fact that he cared for them. I'll talk to you in any way that I please, burned on the tip of Ira's tongue but with a show of great restraint he bit it back, because he didn't want to ruin Bones' chance of seeing her father again, if the damage he had done already wasn't already hadn't cost her. Whatever respect Ira had harbored for Fox was gone with the single notion that if she remembered she didn't care. So, therefore, he wouldn't care about her either, and if it was not for Bones he'd have made everything ten times worse than they already were just for the malicious glee in it. He was miserable so why not share it? Why not be the insolent Princeling that everyone already knew him as? The insolent Princeling that was all he knew how to be.
Bones' pleading made him actually feel regret but not for stepping between them and angering Fox — no for that he felt no regret. Merely, he felt regret for causing Bones pain, for upsetting her.