His mentality is far below that of the philanderer. He is a narcissist in self-destruct mode. He should resign.
That press conference was disturbing on many levels. Not the least of which, was the fact that he talked about himself and his "special connection" to his whore (and that's what she is), than about the unforgivable damage he caused his wife and children.
You're right. He's a narcissist in self-destruct mode who should absolutely resign, before he does any more damage to his family or his state.