If you say that someone is on the edge of their seat or chair, you mean that they are very interested in what is happening or what is going to happen.

For example, most of the time, the audience is on the edge of its seat.

The excitement of the finale had you on the edge of your sea.

They were both playing amazing tennis. Everyone was on the edge of their seats the entire time.

Tradução: na maior expectativa, em suspense, na beira do assento.