gender reveal idea

So I'll be going for my anatomy scan  on the 29th of November. Unfortunately, my husband can't go inside with me cause he has to watch our son (since little ones arnt allowed inside).  I was hoping to tell him the baby didnt Cooperate, and didn't flash his/her parts. Then I'll go shopping for Christmas and one of his gifts will be a box with gender specific tissue paper and baby clothes and toys. Of course I'll film the whole thing. Any ideas from you ladies that I can incorporate?