In the road to divorce and made a discovery...

[Skyscraper]

Ex left a couple of months ago, completely out of the blue. I thought we were happily married. Lots of "excuses" - LYBNILWY line. I have recently discovered that it's likely an ex is involved. I am pretty devastated, though I knows it was likely there was someone else involved I really didn't think going back to an ex from 15 years ago would be on the cards. I just can't get past the hurt. Ex doesn't know that I know....

I'm sorry that you are hurting. Unfortunately there is almost always an OW involved when you get the script. It doesn't matter who it is really and tbh since it's someone who was an ex they were an ex for a reason. Try and be kind to yourself and realise he's not the person you thought he was since he's been lying to you constantly for his own benefit.

Unfortunately men rarely leave a marriage unless it’s for another women. This is usually for the simple reason that it’s incredibly rare for them to leave with their children. Whereas the opposite is true for women. Men will often put up with the most appalling loveless relationships rather than leave children ‘for no reason’ ..
even if no kids, then Home comforts are usually enough for them to stay put when less than happy and will only move on when the same ‘looking after ‘ can be secured elsewhere.
It’s a rare man who leaves just because the relationship doesn’t make him happy.

Please remember, the OW is an ex for a reason. Once the rose tinted spectacles have stopped staring through the haze of nostalgia- he will realise he isn’t 15 yrs younger and neither is she. Classic midlife mania.

I'm sorry you are going through this.
But you knew there would be OW in the background somewhere.
It's a horrible time.
Keep busy.
Get lots of RL support around you.
Be kind to yourself.
Try to keep hydrated and your sugar levels up.
Take it all one day at a time.

LYBNILWY

What does that mean?

OP you need to focus on yourself now, he's left and you need to muster together some courage to get through this. It won't last with this ex, they are ex for a reason. Accept your divorce and don't go looking for answers right now it'll be too much for you to cope with probably, just rebuild yourself up slowly

Love You But Not In Love With You!
I'm guessing.
The usual cheaters script crap.