How do you keep muscles of vagina strong and how would you test this, Serious question have heard may daft theories.
Kegel exercises. I have never really had any problems, even at age 43, with my pussy not being tight or the muscles being weak but kegels are great to keep it that way. They also help me to control the muscles better when fucking!!
Nothing at the moment as its cute and tight enough but I reckon a stress ball might help!!!