End the pattern. No more, "door is open to reconciliation", type conversations. No more inquiring about her life or letting her be privy to yours. The decision to try again will have to come from her and will have to be something concrete, rather than her current b.s. Jet, if she only wanted to try again when the relationship with OM finally and conclusively implodes, will you jump at the chance? I'd make sure you have your life almost exactly where you want it. That way, you can make a rational decision regarding her place in your life and whether she has anything to offer besides, "could have or should have beens"
In the end, it's not the years in your life that count. It's the life in your years. Abraham Lincoln
It is hard to fail, but it is worse never to have tried to succeed. Theodore Roosevelt