My official d-day was Thanksgiving.
Before, when I had suspicions, I only confided in one dear friend.
After, I told WS's aunt/godmother (we were very close), and then my MIL. My thinking was that they would judge him but not too harshly? Which was accurate. They were totally supportive of me and basically would listen to WS's bullshit and then tell him what he was doing was wrong and cruel. When he tried to sell them on the idea that he would have married AP if he had met her first, they called him out on his delusions.
I set a mental deadline for myself of New Years Day -- either the A would be over, or WS could GTFO and move in with AP (and her mother and her adult daughter).
I found out in mid-December they were still in contact/A was underground, so at that point I told everyone.
I remember spending New Years Day with WS's family, and his aunts commenting that I had lost a lot of weight (which was true, like a scary amount), and asking what I was doing. I said I was stressed/depressed. They asked if it was because of our baby, and I blurted, "Oh, WS is moving in with his girlfriend today."
They were shocked, said they had no idea. I said, me, neither.
And then they were like, "Well, to hell with him, you'll have more fun without him anyways."
His entire extended family was incredibly supportive and made it very clear to WS he was welcome at family events, but his AP would never be, and that me & the kids would get an invitation first.
All of our friends were incredibly supportive and while a few people reached out to check on WS, they mostly just were so shocked and appalled they didn't reach out at all.
I found a lot of support in telling people what happened, and I'm incredibly grateful because I was so depressed and every little but kept me going in the immediate aftermath.
[This message edited by ibonnie at 12:36 PM, Saturday, March 11th]