She is one of the few people who knew Peter's secret identity.

Though he will, of course, continue to maintain his secret identity.

I did not believe that my secret identity had been discovered.

Like the rest of her family, she knew about Steel's secret identity all along.

He is one of the few people to known Batman's secret identity.

She is one of the few people to know Batman's secret identity.

His secret identity is unknown to everyone except himself and the audience.

It turns out the psychiatrist has her own secret identity.

In this game, like the movie, she is unaware of Peter's secret identity until the end.

That would raise just too many questions leading, if he wasn't careful, to the question of his secret identity.