When Nick is eating dinner with Alice, he is wearing make-up, goggles and a wig to disguise his invisibility. However you can also see his tongue when he is talking. Making his tongue visible seems unlikely nor was established. See more

Crazy Credits

Over the first minute or so of the end credits we see Nick skiing in snowy mountains, his head and face covered with a hat, goggles and scarf. He comes to a stop outside a large cabin. Alice comes out, evidently pregnant. Nick lifts his goggles and pulls the scarf down from around his face, but of course he is still invisible. Alice kisses him, and takes his gloved hand and holds it to her belly, so he can feel the baby kicking... See more