Switch rotation on click

I’m getting slightly mad with this one.
I have this game object which should rotate (forever) in one direction when a button is clicked.

BUT:

You can click on another button and the object should rotate (forever) in the opposite direction.
Something like:

gameobject.transform.Rotate = Vector3.down * rotSpeed * Time.deltaTime;
gameobject.transform.Rotate = Vector3.down * -rotSpeed * Time.deltaTime;

I know that the rotSpeed neutralizes itself and that’s why the rotation stops entirely when I click the other button.

Isn’t there a smart way to do so?

public class Rotator : MonoBehaviour {
public float rotSpeed = 5.0f;
private int direction = 1;

    public void Update() {
        if(Input.GetKeyDown(KeyCode.F)) {
            this.direction *= -1;
        }
        this.transform.Rotate(Vector3.down * this.direction * this.rotSpeed * Time.deltaTime);
    }
}