Well, if you really want to up the angst, perhaps Jonathan - or Martha - could be hurt in some kind of accident, and it's touch or go for him/her so that the spouse would be torn between staying with gravely injured mate or going to gravely injured son. If it fits in your story, anguished phone calls checking up on Clark would work nicely to up the agony.

Irene

I try to take one day at a time, but sometimes several days attack me at once.