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.)
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.