Michael Harris — the new mayor of a small Louisiana city — tells TMZ his predecessor, Misty Roberts, shocked the population when allegations of her having sex with a teenage boy at a drunken pool party broke.

According to Harris … his prior impression of Misty is that she was a good wife, mother and person … but that image was completely shattered by her arrest and subsequent conviction for having carnal knowledge of a juvenile — a term often used interchangeably with statutory rape.

He said, “I’ll use the word disappointment … the majority of people in town are disappointed. Leadership should have higher standards.”

As we reported … Misty’s victim — who was 16 at the time of the incident — testified her son saw the two of them having drunken sex in the house during a pool party. Her victim also testified he drank so much alcohol he threw up.

To assist in the healing process, Harris tells us the city has “local counselors and local services that are offering treatment to children who have experienced trauma as a result of this.”

If you’ve kept up with the allegations, you know that just reading them could be traumatizing … Misty’s teen victim says he ejaculated inside Misty, which raised concerns of a possible pregnancy. Fortunately, Misty was reportedly on birth control and did not get pregnant.

Harris commented on that part of the case, saying, “As for unprotected sex … I believe in abstinence, but in reality, people are going to have sex. That’s why educators need to teach children sex education. And if they do have sex they should use protection.”