They will feel amazing, like an extension of your ass-cunt. When you push hard while stretching you should even begin to develop a nice prolapse like mine, too. Also just squatting and pulling your ass cheeks wide while pushing hard repeatedly helps, too. Doesn't help with stretching but it makes bigger ass lips and prolapses.
I know what you mean, I wish I could eat out my own ass-cunt. I just have to make do with with the slimy mucus that comes out of me after a thorough internal cleaning.