The most interpersonally intense scene in the entire movie has nothing to do with the awkward ex-spouses rediscovering each other; it's that moment when Alan sees Billy buckling the parasail on and realizes what he's going to do.

Oh yes! That is the most intense moment in the entire film! The look on Grant's face and the way he begged Billy was heartbreaking. Then, when he could not save Billy from the Pteranadons!!!

I really must rewatch that scene and write another JP3 fic :-)