She used to have a Sprint phone, and had never once called her boss on his cell. Then, she drops the Bomb on me after coming home from work on Father's Day. At 10:03pm that night, she makes a two minute call to his cell. He had worked that night with her, and he has about an hour commute, so it'd be safe for her to call him without worrying about the OMW wondering who the hell is calling at 10pm.
PH,
That's it? That's all you got??
That's hardly conclusive. It could be business-related, or just an innocent phone call. Now, I admit, your wife is displaying a lot of classic warning signs, but you need MUCH more than that with which to confront her, or even to claim on her "my wife is cheating on me."