Rotate object continuously and brake

I am trying to rotate an object in unity using oculus controller. I want to smoothly rotate the object in both the directions (clock and anticlockwise). This is the code I have written but the rotation is not continuous and (-ve) direction is not working.

Code -->

public GameObject target; public float speed; void Update() { if(OVRInput.GetDown(OVRInput.RawButton.X)) {

         // Spin the object around the target 
        transform.RotateAround(target.transform.position, Vector3.up, speed * Time.deltaTime);
   

     }
  if (OVRInput.GetDown(OVRInput.RawButton.Y))
     {

         // Spin the object around the target 
         transform.RotateAround(target.transform.position, Vector3.down, speed * -Time.deltaTime);
     }

 }

}