According to Devi, in WMF on page 252, Ambrose beats the women he goes after.
“He beats his whores,” Devi said, interrupting him abruptly. “And if I could kill the arrogant bastard and get away with it, I would have done it years ago.” She stared flatly at Wilem. “And yes, we have a past. And no, it’s none of your business. Is that enough reason for you?”
From that context it sounds like she got together with his at some point and he dared to lay a hand on her OR slept around while they were together and she found out. Either one, I’m not sure, but Ambrose is g a r b a g e.
In a slightly related context, didn’t Denna keep with Ambrose for a bit??? That’s… unsettling as all hell.