My ex liked using the fact that I had other failed (abusive) relationships as a sign that I was bad at relationships too. That I was faulty in some way. I did have a fault, a faulty warning system around abusive arseholes! Everyone else knew they were bad eggs, but me? I let them treat me like crap for a of years just to be sure! And then I would end it once I realised there was no fixing a relationship when the primary problem is the person I'm in it with.
Am I bad at relationships? I don't really know. My 3 main ones have been with abusive men. So I don't really know what a healthy relationship is or if I've ever really been in love (not love bombing, infatuation, FOG, trauma bonding, etc.) what I thought was chivalry was really coercive control. What I through was dating was love bombing. What I though was commitment, was FOG (fear, obligation, guilt). What I thought was a deep connection was trauma bonding. I thought I'd found a kindred sprit, when really they were mirroring back to me who I wanted them to be.
I haven't had a new relationship since, but I have educated myself so much on this stuff and I now know my fault was not in ending these relationships, it was letting them fresh on so long. It was in continuing the relationship due to the sunken cost fallacy, and not running at the first flap of a red flag. Hell, I walked straight past the red flag bunting right into another abusive relationship because it was familiar to me. I actually thought that the fact my ex wanted to have me all to myself meant be loved me more.
Now my biggest thing is to trust other people's warning systems about prospective partners. If my kids don't like someone, or my friends don't or my mum doesn't, or dogs don't like them, or they are rude to the waiter, it doesn't matter how frigging lovely they are to me in those early days. It doesn't matter how many redeeming characteristics they have. My warning system around abusers is faulty, but everyone else's isn't.
Sorry, the long way round to my point there but, my general point is that if your boss can see it, if your kids don't like him, if even your warning system is telling you he's a bad guy, then LTB. Maybe not immediately but start making an exit plan because this will not get better. He's shown you his true colours and you and your kids deserve so, so much more than this