So your husband feels like he is bumping into metal and it hurts? Trying to understand what is going on. You don't have metal in you most likely. :>) You do have a pubic bone. Not sure if that is what he is feeling.
Could it be:
- a forgotten tampon from the end of your last period?
- genital warts?
- your pubic bone?
I don't think any of those would cut him, but there is a slim chance that a genital wart could feel that rough. Can you feel anything inside your vagina with your fingers? (Be sure to wash your hands really well before checking.)