I can’t answer your question from experience either, subjohnny, but another place which sells a similar device has this to say:
Q: Can the Original Vee-String? or Bladder Vee-String? vagina be penetrated?
A: Yes. They are modeled to the size of an adult female vagina and can be penetrated by an average adult male penis. However, there is no canal or sleeve to accommodate the penis. There is just a slit in the bottom of the vagina. The latex memory allows it to stretch and return to a normal size. Treat it as you would any female vagina…with tenderness.
(The site for this one, btw, is http://www.castlesupplys.com/ – with which I am in no way affiliated)
HTH!
xox
Cherie
—wondering why it is that the subguys don’t put these posts in the sissy forum?