Ex left four years ago after I discovered an affair. He's still with her. During this time I have desperately tried to instigate regular contact but it's very sporadic. He sees them about four times a year. A few months ago I told him he needed to see them every other weekend to build more of a relationship. It started ok but he lost interest and it's been 4 weeks since he's seen them. On the last visit they saw save the date cards and future Mrs mugs etc. They know he is getting married but he has not told them or invited them. I feel hurt on their behalf. I don't care that he is marrying her. She removed a lazy lump from my sofa but is not involving his children in his wedding normal? The are 16,11,10 and 8 so old enough to understand.