The good news is, since the grandparents, unlike Vasily, don't have presumptive custody rights, they probably don't need a Gregor-sized ace in the hole. (And, I know family court judges are a mixed bag, but now I'm imagining the grandparents actually trying to get custody, and there's an exceptionally world-weary family court judge sitting on the bench with her head propped on her hand listening to the grampers' impassioned pleas of "They let them climb on playground equipment, Your Honor! And go up stairs! STAIRS!! And play in a pool with only their mother to watch them!" And the judge is like, "... so you're complaining that your son and his wife are good parents with healthy active children?")

Co-signing the strategy session. And also FSM bless parents who are willing to make it clear to their children that not all the adults in the family are in fact responsible.