lwb - I don't think anyone much is saying don't contact OW's H - rather just to wait and do it with thought and not anger. That way you can be sure to get the message across how you want it.
I know you have this 'agreement' with OW's H and you feel you owe it to him but please just don't trust him. It's easy to empathise with the other injured spouse in this sitch but ultimately he will look after himself and his family and I do beleive if that means backing his wife up at times he may well do that. So just look at him a bit sceptically and always wonder what he may gain from any given situation as well. I am sure he is a nice man but he is also a desperate one I imagine.
I am so, so sorry you are in this place.
saffie
Saffie me 46 H 46 M in 1986 D20,D18,S16,D13 H's A 01/05 to 07/06 H recommitted to M 07/06 renewed vows 09/06 Going from strength to strength