You don't have to tell your W clearly, "Don't go," or "You can't go," for her to have felt your disapproval, as Sunny points out. I know that for me, it's stressful to have my SO upset with me, even if he's being unfair. That part is *my* issue, and my guess is your W has hers as well.
You're in IC, right? Sounds like perfect therapy fodder.