Imagine. Her delicate flesh tearing at your will. Your smug bliss knowing that you're destroying her more and more with each thrust. Her screaming making you even harder.
Imagine the sheer horror in her face when she understands that she'll never be able to feel any pleasure down there. She'll never experience anything but the agony of being used like the whore she is. She'll never recover, she'll always be your worthless cumdump.
After she's properly tamed you could even untie her and just keep going, she won't fight back. She'll cry, she'll beg, but she won't try to run away because she knows that the punishment would be worse. Little does she know that even if she acts like a perfectly obedient pet, you're still going to have fun with that broken bottle you're saving for her.
She's your toy and no one said that you must treat a toy with respect.