Liz, if it was me and AXH, I don't think I'd engage with AXH if he pulled that with DS. Though I would definitely sit and talk with DS. The reason being, there is absolutely nothing I could say to AXH to either change his mind if he actually thought I was 'pawning DS off on him' or that would get him to stop saying that s--- to DS. However, I could help DS work through how he felt. And if DS didn't want to talk with me about his dad, maybe a counselor could help him.
It's not my place to _make_ AXH have a relationship with our son. All I can do is facilitate the schedules for the visits as outlined by the visitation schedule, and make sure DS is safe for those visits.
With your XAH, do you think saying something to him would actually help?