Perhaps it's because you say "cheese" when you smile falsely for the camera.

Jason smiled falsely and pointed to the ground near the big herbivores.

"Hey," he said, smiling falsely into her eyes.

The Prince, however, smiled falsely, straightening up in his chair and running long white fingers through his blond hair.

I will,' Sarah said, and they smiled at each other falsely, knowing that nothing of the kind was ever going to happen.

We smiled at each other quite falsely, but the others bought it.

Their untruthful eyes smiled falsely at each other.

Creslin smiles falsely, and his stomach turns again.

Sometimes, at table,' she smiled falsely, 'my husband was like you, Sir John.

For days after his face had seemed stiff from the effort of smiling falsely at a hundred people he hoped never to see again.