It's not a big deal...

I honestly am thinking your wife is getting some perverse pleasure out of making you squirm and pursue her like this...

Each time she throws out the "I'm leaving" and you show a negative reaction your wife gets her fix.

I am thinking on the best way to handle things... Divorce-busting is not my strong suit, its affair-busting and you pretty much put an end to that I'd say... Excellent work there btw