Older Children and my partner

I feel like I'm stuck between the devil and the deep blue sea as my daughters have declared that they want me to leave my husband and think I am unhappy with him. He has, in the past, been wayward and went through something of a mid-life crisis where he had a number of short lived affairs and left me for a few months. It made him (and me) incredibly unhappy and so we decided to work things out, which have happened. But this was 7 years ago and although life isn't totally perfect it is certainly good enough to be more than acceptable and I would say that I am happy and my OH has done more than he needed to to make up for his errors, including looking after my children (both nearly 30) where he can with practical and physical support (helping to move them, welcoming them always to our house, all on top of everything they did when they were growing up including teaching them to drive, etc). Their father was incredibly lazy throughout all this time and also very selfish but of course he is the hero. They stated that I left him for much less than the OH has done (but they don't know the half of it as I have never told them). Now I feel sick as I really think we have got somewhere - a new home, new jobs and also plenty of good support to keep us going in the right direction. Their comments came because they thought the OH was flirting with a particularly predatory friend at a party (he probably was but I know what the woman is like and don't take it seriously at all). They completely lost their rag and caused a huge drama. They were going to continue in the morning and leave without saying anything until they realised I was very upset - not least because the OH said he would leave rather than see me have to choose between him and them, as he knows he 'doesn't deserve me'. This seems ridiculous after 7 years of putting things right and making sure he tries to make me happy, which has pretty much worked out. Everyone has now said they want to move on from the incident, but it has made me feel very down and I wonder if there is some advice out there to help?