Lighting, Reflections and Render Layers

Hi!
So, I have this simple scene with an object, a sphere and a lighting setup. I assigned the sphere to render layer 1, the object to layer 2 and the lights to layer 3. The sphere’s material is highly reflective.
Now what I’m trying to achieve is to have the lights interacting with both layer 1 and 2 (sphere and object), but I don’t want the sphere and the object interacting between themselves (I don’t want the object to be reflected in the sphere).
I can’t seem to manage to obtain the desired result. What is the best solution for this?
Thanks.