She is defiant

Evellyn’s eyes flash with stubborn pride, despite her degraded position. You see the way her body responds to your touch, stiffening here and quivering there with pleasurable ripples; she’s still playing the game of plausible deniability, you suspect, even if the signs betray her outwardly. She can’t admit it. She has to resist, it is expected of a lady. So much the better. You’ll gladly leave her in that pit of humbling she’s dug for herself, even if she reflexively believes it to be her ladder back towards dignity.

”I’ll never submit to a lecherous pig like you, you… bastard!” she hisses.

”You’ve got grit, missy, I’ll give you that. All the more fun for me, I suppose.”