I'm no MLC expert but you asked if we can tell you. It feels like he is running away from the challenges of life...career not working out, a difficult parenting situation, and what to him might feel like a loveless and sexless M...and into the arms of the OW. Those are signs of panic, immaturity, selfishness, maybe depression, maybe MLC. Is he obsessed with aging/youth, working out/appearance, fear of sickness/death? Have you read that famous John Updike novel about a man like your H who is trying to run away from his life and makes messes wherever he goes?
Gordie 40s W 40s M20+ kids 2016 BD W fantasy affair w OM1 I do everything wrong 2017 I start to DB W says TLTL files for D PA w OM2 2018 I do LRT W drops filing and OM2 situation slowly improving