Sensitivity Makes Me Freeze Up When I'm About To Climax.

I wanted to see if any of you could help me with this, which has been a bit of a growing conundrum in my sex life.

I've heard reports of drastic sensitivity post orgasm, but my problem is while I'm going through orgasm. I try to keep going but my muscles contract and I stop, I can't move. I feel the orgasm, and it's pretty good, but I paralyze, and it becomes almost painful if my partner continues the motion. Again, this is while I'm coming, not afterwards (although I am sensitive afterwards but I figure that's normal)

Any tips, ideas?

 

This could be a form of vaginismus.
See your gynecologist for diagnosis.