Wellington grieved for weeks after we lost Napoleon. He searched and meowed and cried and wanted reassurance all the time. He didn't fully get over it till we got Biscotte, but now he seems to have transferred his feelings to her, and is not pacing around alone any more. He is still very affectionate to all humans, but no longer has the question in his eyes all the time that I grew to hate, as I could not answer it. So I would say be very loving to little Harley and maybe think of getting him another playmate when you can handle it - a difficult thing to do, I know.