I organized one for my husband many years ago. It turned out perfectly and was one of the more memorable events...he had both his dad and stepdad, all his relatives and our cat ended up in emergency surgery....kitty is till with us and the party was such a success.
His uncle & aunt were the only ones in on it, the uncle took him riding while his aunt said she was too sore from last time--of course I had to stay home with her,lol!! They were at our house. Hauled ass to the store and bought seafood and a cake--wanted homemade but no time--and got cooking!! The guests pulled in and parked in the back yard--not visible from driveway--and when he got back from riding (it snowed) he was soooo surprised. Then the vet called, had to take kitty in while his aunt stayed to cook and said he needed surgery for kidney stones....All in all, a wonderful day, though.