If you're going to be neither a friend who admits to being biased nor an impartial reporter, then you should leave Mayor Morse entirely alone. I don't think that he or anyone with whom he had relationships needs more publicity.
He didn't ask you to defend him. He was glad that you did, but it might have been safer for him if he had realized that you had prioritized his political platform above all other considerations. He did not ask you to create a hostile environment for people who might otherwise have spoken up about being made uncomfortable. If those people do start speaking up, it's going to be national news, because of you and those who rallied around you, some of whom are formidable people and organizations.
He was too young to be Mayor. Also, sadly, although a working class background can bring insight to office about the mentality and needs of more diverse groups, it does not necessarily bring savvy about personal behavior. There are a lot of unspoken rules on the way up the socioeconomic ladder; some are fair and some aren't. He broke the ones that are, perhaps having confused his professional success and subsequent approval with a license to behave as though he weren't a public figure and an educational authority. As far as currently known information indicates, those were youthful errors; please don't make them or him worse by continuing to portray reasonable criticism as homophobic.
Investigations are pending. Wait.
If reporters are going to start soliciting information from people who have had relationships with Mayor Morse, I don't think you should be one of those reporters. It's what you should have done when you heard about it, if you thought the school's investigation wasn't going to be sufficient. Having supported him so impartially, it would be wrong for you to start tearing him down now that he has lost.
What everyone could do is trust that the investigations have enough integrity that people who feel wronged or who have concerns will be heard. Everyone can wait, for the sake of all those connected to the situation. There is no need to haul people out for a story and then meticulously disillusion them after you lose.