We arranged a sensible, workable system dealing with skid visits over the past 10+ years:  They treat me like crap, so they don't visit our house. I have never discouraged DH from seeing the spawn, so he travels to see them, has even taken his son on vacations (son stayed on phone/laptop the whole time in the Caribbean). I always used the visits as spa time and uninterrupted girlfriend time. Through the years, we relapsed maybe 4 times and had skids at our house, thinking they had matured. Nope. The most recent visit here was when DH was ill (when I joined ST) . . . skids were horrible; it was a total nightmare.

DH planned a recent 4-day visit to spend time with the skids for a couple reasons: His son is moving far away (35 yo has been living with mommy); and SD's oldest's birthday was approaching. It always takes DH days if not weeks to let out to me what "really" happened during his visits. . . the downside. He stayed at SD's house (usually stays at a hotel). Of course, his visits are like the Disney Dad visits where he takes everyone out and pays for everything multiple times. Probably doles out cash as well (we have separate accounts). The family is bigger now, with a son-in-law and more (long, complicated story). But, DH recently revealed to me, his son only spent maybe 3 hours with him--and that time was at a restaurant/bar where DH was footing the bill. It deeply hurt DH's feelings, particularly in knowing he wouldn't see the little ahole for perhaps another year or so. Spending time with ahole was part of the reason for his trip. (DH has the health issues looming over him and always on his mind.)  Note this was a long weekend and SS only works p/t hours during the week and DH was made aware that SS was spending time with his guy friends. 

I said to DH, "Since you were in their territory/her territory and SS is staying at her house, it would be seen as a betrayal had he spent any more time with you--and he's still sucked into all of that, like a child." Without a doubt, the ex gets pleasure taking jabs at DH through the kids (I used to see it especially via social media--I erased those connections long ago). It has gone on forever. And the skids (because this is on them, not her) don't have the backbone, integrity, or decency not to play along. I also believe that they like shooting arrows at DH. I believe they have grown accustomed to it and enjoy it. It's fun to hurt Daddy's feelings, punish him, remind him of where he stands. I wonder when he will tire of it--if ever. I keep re-focusing him on my family members, the people in his life who treat him with care and respect. . . even the little 5-year-old who asks about him all the time.