IDK, Caigy... I think, as a right of passage (at least for guys), leave it to S17 unless he asks for your help with something. That's just my thought.
It's a blessing and a curse, to be finding out about your H's words regarding you, and his actions (such as with the incident with D14). You get to have a gauge on his crazy-o-meter.
Support your kids through their drama with your H. Remember though, if you did not hear about this stuff regarding your H, then you'd be wondering about how he felt, yet... your life would be much more peaceful because you don't have to hear about or deal with his drama.