I have always been concerned about this question, because... I never succeeded myself.
I would like to learn how to open the anus by simply spreading the buttocks with my hands. I can’t do it in any way, even after a 3.5cm phallus. It will open a maximum of 2-3 times after being pulled out and that’s it, it’s closed again.
Once it happened early in the morning, when I woke up, the butt opened on its own. Apparently the muscles have not yet understood what is happening.
It doesn't work anymore.
My wife also does it easily, just knee-elbow position and relax. The butt opens to the size of a 5 ruble coin even without hands. Although she was hit in the ass a maximum of 4-5 times.
Maybe there are techniques or special lubricants?
