No, but I'm sure there are ethics laws and sexual misconduct laws governing people in public office. Similar to how there are such laws governing every other citizens.For one, he had sexual encounters in the people's house, inside the oval office.
Having sex in the Oval Office is illegal with extra penalties if you do it on the Resolute Desk?
In today's world, sexual harassment is levied so easily. Even if you have consensual relations with a co worker, the company can still fire you for sexual harassment if the other party makes any kind of complaint about it. Same principle applies to a president.