"It was meant to be painful!" she snarled, her lips positioned close to his left ear. "You're nothing but a fucking stinking piece of shit and I can do whatever I like with you! You deserve everything you get!"

"Yes, Mistress Isabella! Forgive my impertinence!"

Relishing being nasty, she moved her right knee, using it to torment the tenderised flesh of his right thigh and buttock. Slipping her left hand under him, her fingers coiled about the most amazingly-stiff penis. Glancing over her shoulder, looking towards Brittany who was beaming her approval, she said, "You're right, Mistress Brittany, this dog has a truly fearsome hard-on!"

"It's amazing but true; many a slave does get an incredible hard-on when they've been beaten. They're really only dirty sex-mad animals. It's a kindness to wank them off. So, Mistress Isabella, jerk him as hard as you like! Let his cum paint the toe of your boot so he can lick it off!" Brittany commanded.

Strengthening her grip, Isabella callously pulled his cock downwards, towards the gap between his legs, hardly bothering as to whether her action was painful or not. In order to partially support herself, and in the hope that her rubber-clad body would somehow torment his flesh, she leaned forward, pressing her right shoulder into his back, using the inside of her right thigh to rub against his. Making no attempt at finesse, she jerked her left hand up and down his shaft callously. "You like that, don't you?" she stated rather than ask. "You like your Mistress Isabella jerking you off, don't you?"

"A-a-ah! A-a-ah! Argh! Yes, Mistress Isabella, Mustapha is a dirty dog. He lives to please his pretty mistresses!" Mustapha appeared to be transported to some sort of earthly paradise, his body tensing with expectation.

Putting her right foot to the floor, Isabella lifted her left leg, slipping the boot between his legs. "You like that! You like that!" she chanted, masturbating his cock ever faster, ever more forcefully.

"Yes! Yes! Yes! Mistress, please relieve me of my offending erection!" Mustapha responded. Moments later, his penis spurted jets of white cum, it splattering all over the front of her red-rubber boot.