At least mostly.

It sounds like you have the type of relationship with Milt that you can be frank.

"Milt, about that money for the boys. I suggest you put it in writing. Just to be clear."

If you decide that you don't want to make Milt confront the reality, of his prognosis or his end run around his own sons, then you might as well forget the conversation ever occurred. It will be up to Milt's sons to decide what to do.

Maybe later, when it's over, you can take your ex aside and relate the conversation to him, at least to the extent that Milt told you he wanted the money to benefit his grandchildren. Maybe your ex can process that and find a way to make that happen.