yes... I mean no. only if mid grindage your panties and his boxers get removed. It is possible however to penetrate with the aforementioned articles still intact and I imagine that the spermatoza would not be hampered by the mesh of fabric. But it is really a job for sperm to make it all the way down the canal in good conditions with all the invaders it must face with acid and convolutions, navigations and circumventions of the vaginal passage and all. Don't risk it though. It also hurts after a while and he will feel like freeing willie at some point. I did.