Turning A Female Ass Into A Second Cunt

I have tied down my female slave bitch, with her legs spread and raised and her ass and cunt fully exposed. Today I’m going to work on her tight ass hole: I want to stretch it as wide as her cunt. I took the biggest dildo she can take in her pussy and I will use it to open up her shitty hole. It takes a lot of effort to introduce just the tip and I have to push really hard to insert it full length. Now I start pumping her really hard and deep. I stop only when I’m exhausted but her ordeal is not over yet. I want her ass to remain permanently stretched, like a real cunt, therefore, I push again the big dildo in her ass with my foot. I let her there, tied, with that pole inside.