In my wife's case it was definitely MLC first. I can track the trigger back to 05 and can see the changes in pictures over the years. Her 1st affair wasn't until 10/08. But prior to that there were instances where she would say if different things would change she would be happier. The changes she wanted would happen and it would appease her for a short period but then I believe the pain comes back.
It's the depression that cause these behaviors. THere's a void that they feel is there and they're trying to fill it. Short term highs whether it be infatuation, drinking, buying stuff etc
