Linda, Many mlcers will encourage their spouses/mates to date and get involved w/others. It's a way to alleviate some of the guilt for the affairs that they are having. They can also then say, well you have a new boy/girl friend, then it's okay for me to announce that I have one too.
It's very normal mlc thought processing.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.