I suspect that often the WAS feels trapped in the marriage and wants to get out and date others so as to help them feel less trapped. But they never really consider that the LBS could also do the same.
It seems as if the prospect of you dating has helped your W to realize she could easily end up losing you.
The dating scene can be fun, but it has its own drawbacks. I'm in touch with 4 different ladies right now and it can be quite the juggling act.