I've been through my fair share of those situations.

And each time - nothing ever happens!
I think re-connecting with an ex is a fair bit of fun actually. Its always nice to know how people you've known are getting along these days. Ex or not, there's no intent to cheat there, its just plain old curiosity. Would your wife still have gotten jumpy if it was an acquiantance that added you? A female one?
Its just like adding an old classmate on facebook for me.

It makes me smile, to see that they've gotten on in life, as i have, and it only serves as a closure in a past chapter of my life.
To think of the if onlys and the had beens and the awesome sex that we had - or more of the rough, animalistic-rabbit love we would be having if we got it on behind my girlfriend's back, well.
That's just fantasizing.

I'd be wasting my time, innit?