what's-his-nuts
A phrase to refer to a guy when you can't remember his name, similar to what's-his-name. Also the masculine version of what's-her-tits.
Example:
You want tix to the show? You should talk to what's-his-nuts -- y'know the guy, Mark's roommate.
You want tix to the show? You should talk to what's-his-nuts -- y'know the guy, Mark's roommate.