@firefly2842,
Fairy Tales have happy endings and we as children remember all too well the Prince, the Princess and happy endings and so no matter how old we are in life, we'd like to believe that exists, is real.
I say this because you are looking at your pending Divorce and him being a Widow as "meant to be", I think. But no one really knows that, it develops firstly as part of a "dream".
Sometimes people come into our lives for a reason. Perhaps this man came into your life to show you what "being together" without sexual contact and enjoying that company over and over, each time, was the lesson, reason and you perhaps sub-consciously realised the man you were with couldn't give you that.
Perhaps this guy is the "dream" guy and the end becomes a fairy tale. Who knows.
At this point in time, there should be no guilt as you state it's amicable in-other-words your Husband also feels that it wasn't to be.
But also at this point, this co-worker trusts you, he had an emotional affair with you, perhaps needs someone to talk to, lean on a bit but in addition, he would be hurting, in pain. Death is a horrible thing.
Be his "friend" at this point in time and only his friend. Don't look into things.
Let him grieve.
Most good friends remain so for life, or go on as being one person, yet two.
What ever will be will be.