it's not so much that they should intervene in terms of his mental health, because if he needs help, it is his responsibility. it's more the fact that they don't seem interested in ensuring their grandkids are safe, and especially the way they treat his kids - and not just the step kids, but their three biological grandchildren - so differently to the kids of Chloe, Millie etc, paying for them to go on trips to Disney and mentioning their birthdays on SM etc - Chris' kids are always left out and - worse - seem to be living in a very chaotic environment. if there was any risk of SS involvement, as a result of Nicole and Chris' volatile relationship, surely as their grandparents, you would step in to help and protect the kids? i'm not saying they should get involved in Chris' relationship and fully agree that Nicole’s parents also have a responsibility as grandparents - but we have no idea how involved or uninvolved they are in the kids' lives. Sue and Nowull make it very clear that they aren't bothered, by ignoring the footage shared by Chris and focusing on shopping sprees and decorating the house for Christmas - and even if that isn't a recent video, holidays and shopping were still their priorities whenever that was happening. plus they seem to have happily welcomed Chris back into their home, fully supportive of him despite his violent behaviour - in the same way their other violent son.
sure, they're his parents, but it sends the message that they don't have any issue with his behaviour - despite the fact that Millie potentially experienced domestic violence, seems pretty crass to then allow Chris to move into their house. perhaps, instead of chilling by the pool, his parents could have reached out to him when he was struggling whilst they were in Florida, and asked how they could help him, instead of ignoring his references to feeling suicidal, which he shared on. SM. as he was obviously desperate for support.