Please help with the Harry Potter Lego wii game?

So in the Lego Harry Potter Wii game, Years 5-7, I'm on the level called 'Just Desserts.' I'm in the 3 Broomsticks with Slughorn and he has the grey nube, nuvola over his head. I've solved how to get the Butterbeer but it won't let me hand it to him! The grey nube, nuvola won't go away! I've searched how to do this everywhere but I've got nothing. Please help me, this is driving me insane!