An extension of Peter7 where the girls are just as ugly but the guy scores her higher so he can appear to be a mack. In reality, he is just trying to show off and is in denial.
1) That's not a Peter9. She is as ugly as a peter7
2) Peter9, Peter7, they're all the same double baggers.
Peter: That girl is a peter9.
Mike: No Peter, that's a true peter7. Look at her FOBy dress.