Whoa!!!! LW is spot on feeling strangely that grandparents are violating a boundary here.  And since they have demonstrated its on with them to be nasty and hurtful and then pretend it's fine, do young children really need to be alone with them?  It's better to tell the kids an age appropriate version of the real story:  grandpa and grandma .... Insert age appropriate explanation, and so right now visits are not going to happen.  Express empathy for their feelings by explaining yes this is sad and sometimes these things happen, etc. I don't have a good script.  But the grandparents who try to do an end run around parents, over freakin money?!? I would guess there's some other potentially new serious dysfunction.  These guys can't be trusted to care about their own children's emotional well being.  Why place a defrnseless child in that???