WH's oldest, best pal is now friends with the OW and trying to make sure WH will dump me and be her man. After all....I am the 'ball and chain', the dead relationship that sucks his life force from him to keep him from truly living (lol) and she is the 'passionate love' (my statement on this.....bull, friend is clueless about love and commitment and happiness from working through issues... lol)

I hear this from a reliable source though I know I should not be hearing this drama stuff.

1. I never liked best friend but was civil to him for 25 years
2. I know he is whacko
3. I hear it and think that I don't want friend ever in my life again even if there is a rebuild marriage (he could be a source to contact OW in the future now that they are phone pals)
4. My kids are exposed to friend when they visit WH

How do I keep cool and not get sucked into this drama and be true to plan B?

I am in your same situation as I also hear things that are upsetting even if I am in plan B.
You have to tell people not to talk to you about H. I know you are curiuous to know ( I am!) but then it hurts too much.
There is nothing you can do about you H best friend and his siding with him. It happens and there are also IL that at times side with WS...there is nothing you can do unless you are able to get full custody of your kids; then they will not be exposed to H at all. Can you do that?
Really plan B is for us not to get hurt. WH will do and say things that hurt us. Let not allow them to hurt us. We no longer need to investigate like when we were trying to uncover the A. Now we can pretend they do not even exist.
We have to do that otherwise we will go insane!
blessings

As atena said, you must insist to all of your friends, relatives, co-workers and acquaintances that they tell you NOTHING of what you WH is doing. NOTHING.

If they try, then you walk away, hang up the phone, block the email - whatever you have to do.

This is about protecting yourself. WH is not going to do it, so that leaves you.

And remember that WS lie, and lie, and lie, and lie some more. Some of the crap you are hearing may well be lies and exaggerations to try to get a response out of you - but you have no way of knowing and right now it doesn't matter anyway.

Do not let one drop of it through!
Mulan

By exercising self control.
The same sort of self control we ask waynerds to use when they are tempted to "check in" on OP. Or tempted to have one more "closure" event.

I was caught off guard in a conversation.

We weren't even talking about WH and then this person (friend who apparently is an enemy of the marriage) came up in the conversation and the person who told me said

"You know, ______ is OW's friend now and calls her up to counsel her on her relationship with WH. He is pushing WH to file for divorce from you and move on to greener pastures."

It took me totally a moment to think that it was actually about WH.

LOL.

At least I now have a clue that the story on the other side of the fence isn't all a bed of roses.

My side....sort of IS (a bed of roses). I am enjoying life. A lot.

Don't you hate it when that happens?

For the next "caught off guard" moment .. have an action prepared. Something like:

"Wait. Stop. It hurts my ears to listen to anything regarding the infidels. Please change the subject."