How can I get one of our cats to stop vacuum-eating?

I am not sure what to do about the "retaliation behavior" except possibly get Feliway, the calming pheromone spray or plug in. Is he fixed? As far as feeding, my mother had a similar problem with a fat cat and a skinny cat. She got a plastic storage tub and cut a hole in the side just big enough for the skinny cat to get in, but not the fat cat. She left food available in the tub all the time for the skinny cat to eat, but only fed the fat cat twice a day. Also, since your roommate's cat gobbles it down too fast it must be given food in small portions.