You can control how much you share via F/F. If you're not on the same resort reservation, or sharing any common plans during this upcoming trip, make sure you're only exchanging "Only Plans We Share" in the app. You go to the app, Profile, F&F, then click on the individuals you want to keep your plans secret from. Once you are there and they know you're there, you could switch it back, if you wanted to. Hope that helps and hope the surprise goes well!!