You're wrong. She was the Appointments Secretary for the Mayor. She worked for him.
She's also thinking of suing him for sex harassment now.
Oh.
Anyhow, I actually don't think it should be illegal as long as it isn't used to hire or fire someone, I don't really care who he bangs as a matter of law.
That said, the fact that the guy would bang his campaign managers wife shows a stunning disrespect for his friend, his wife, and makes him untrustworthy. I certainly wouldn't vote for him.