Hmm, depends what way you want it to go - you say a tragic divorce - are kids involved? What is so tragic about it? Do you want it to be a sick thriller with him obsessed with her, spying on her every move etc, maybe get a job as her boss, and bring her down that way with lots of twists turns etc?
Or is it funny/sad - Maybe he could fall in love with someone else really annoying/ unlikely right under his nose whilst still pursuing her? Or do you want him to get her back happily in the end - haha he was the right guy all along after lots of other dates or maybe move on in other ways - depends on the moral of the story? You have only given the first taster this could go anywhere- what are you thinking?