After you put the cap back on, put his deodorant back in his manly "Love / Dream" flower box. Now just sit back and wait. For more fun pranks, clic...
The cream cheese deodorant prank is a simple prank that takes next to no time to set up and is sure to make you laugh. (I can't guarantee that the person having this done to them will see the humor in it.)
"Borrow" his deodorant. Then find some cream cheese and a small spoon.