Then he grinned like a man with a secret joke.

Barnes laughed, as if he had touched on some secret joke.

He seems to be enjoying a very secret joke at somebody's expense.

The women were beside the pool, laughing, sharing some secret joke.

One corner of his mouth curled up, enjoying a secret joke.

You only get that expression when there's a secret joke.

She laughed as if at some secret joke, and then let Xylina in on it.

He wore a look the tribune knew well, as if inviting him to share some secret joke.

That was the only word to describe them: she always seemed to be on the point of sharing some secret joke.

Corsi grinned, as though someone had just told her a secret joke.