I know it's hard and I really feel for you, but let her be. Don't ask her questions about where she is going. You're doing so well on so many other things. It sucks that she's going back to behavior that pushes your buttons, but pull a 180 on her and just let it go.
Remember not to assume anything. Also, if she has tried breaking it off with the OM, it is possible that he's putting up a fight and not making it easy for her to end things.
Hey, and if she really doesn't want to do presents that lets you off the hook. As you're a photographer maybe you can take a nice photo of your kids and give that to her.
