This is a long and kind of complicated story... I will try to explain best I can.
FI are very good friends with this couple. FI is godfather to their son. FI works with the husband. I'm very good friends with the wife. All three family members are in the wedding (BM, GM and RB). We have always had a really good friendship all the way around.
A few months ago, the husband cheated on the wife

Wife forgave him, and they have been working on their relationship. Thankfully, the son is 2.5 years old, so he doesn't understand what has been going on.
This past weekend, I talked with the wife, and she said things were turning for the better. Unfortunately, I got a text yesterday from the wife saying she caught him cheating again. The husband told FI that it was done and that the wife was out of the house.
I'm so confused at what to do! I have texted the wife, letting her know of my support for her. Ever since the first cheating incidence, I have not been "accepting" of the husband. I was always pulling for their relationship to work out, and supported them. But I wasn't going to be the first one to call him up to hang out.
The wife needs my support, and I'd love to cut the husband out of our lives. But he works with FI (and will eventually own the company so he would be FIs boss). Plus he plays paintball with FI. I want to support the wife, but can I do that to her "loyally" (not the word I mean, just don't know how to convey what I mean) while keeping him in our lives?
CN: Two friends are married. Man has now cheated twice. Can I help support the wife while keeping him in our lives?
Thanks