Christmas gift help

Okay so I bought my brother a grill for Christmas. my mom and I came up with the wonderful idea of having him assemble the grill not knowing it's actually his by pretending it was for my husband. (My family loves to mess around when it comes to Christmas gifts) i figured I would give him a grill related item that is super hard to open (I'm talking zip ties Saran Wrap the whole nine yards) and that would be the big hint. Once he figured it out he would go check where he put it togather and there it would sit with a big red bow. So I asked my brother if he could help a poor girl out and he agreed but when the day came for him to come to town (they live away from me) all he could do was pick up the thing and deliver it to my aunts (where Christmas will be held) due to Christmas shopping time just ran out :/ so now I'm stuck with an unassembled grill and I already bought and wrapped (and zip tied) the hint. I don't know what to do about the grill. He won't think to go check anywhere since he built nothing. If I wrap it in the box he will immediately know once he sees it near the tree and the big hint is ruined.