He's keeping something from me

No, it's not a cheating, dirty-liar kind of secret (at least I hope not!), but it's a secret between us that's driving me nuts!
Mr. Snowflake told me last fall that he had a surprise for me at the wedding. I'm not good with surprises, I HATE surprises (worst b-day ever, the year a surprise party was thrown). So the thought of something being sprung on me in the middle of the wedding drives me NUTS! (Remember, I'm a major planner and a little bit of a control freak - I'm not a fly-by-the-seat-of-my-pants kind of girl) Lately I've been working on a schedule that pretty much accounts for every moment of our wedding weekend. In the midst of asking him to take care of some band details, I followed up with a question about the surprise, when is it going to take place, etc because I needed to put it in my schedule. He told me not to worry about it, it's all planned. I told him he didn't have to give me any details, I just need to know the time and the amount of time it'd take place. He shot back that it was all scheduled and I didn't need to worry about it. Then I started getting pissed because it wasn't in MY schedule.
Needless to say, he still won't give me ANY details. It's SO frustrating! He just keeps saying it's taken care of and in our schedule. Now I've been over that schedule a million times and have combed it and perfected it to a T, there is NO surprise scheduled anywhere in there, so how can he tell me it's all planned and scheduled? Augh!
I guess I just need to calm down and figure out how to work my girlie magic to get it out of him - or maybe ask him in his sleep :)
What surprises or secrets has your FH kept from you?