Here's what my MC and DB coach both said, regarding the issue of children and the possibility of divorce.
1) Unless you are certain, 100% that a divorce is happening, say "I sure hope not" when they ask about it. Also say something like "B/c I have loved your dad a long time" or "we're having a very rough time but I know we both love you so much"...and if THEY identify a bad behavior of your h's, how he mistreats you, etc. you can say "that did hurt, but there are a lot of things I still love about your dad b/c he has lots of good qualities."
2) If you ARE SURE of a divorce, then wait til it's closer in time to happening and not a year down the road. You can say "it seems to be happening but won't be 'done' legally until 'x'..."
No matter what, it's key to do the following: 3) Stress to the boys what will NOT change in their lives, no matter what happens.
Meaning, if you know you'll remain in the house, or the same area, stress to them that their friends/school and neighborhood will remain the same. Not all of their lives will be turned upside down. They won't be on the streets...they'll have two places to visit and sleep some nights, but they still have TWO parents who love them.
Whatever changes happen, you'll minimize as well as possible, For instance, if you do move (reasonably close) then tell the boys that you'll drive them over to see their friends, and so they won't lose everything in their lives.
If you must move far away, say, to be closer to family, stress that they'll be able to see and bond with their cousins more and see grandma more, etc.
Hopefully, as little as possible will change for them.
Good luck!
M: 57 H: 60 M: 35 yrs S30,D28,D19 H off to Alaska 2006 Recon 7/07- 8/08 *2016* X = "ALASKA 2.0" GROUND HOG DAY I File D 10/16 OW DIV 2/26/2018 X marries OW 5/2016