Re: Jealousy problem-3 cats. Please help prevent re-homing!
Welcome, and I'm sorry you guys are having such trouble. I am not very experienced in this area, so I'm hoping others with more experience will chime in.
It almost seems as if your cat is behaving towards your wife as if she were a rival, I doubt this is from jealousy, but I wonder if it is a 'different smell' sort of thing. Ack! It is late and I'm not making much sense, so I'll keep this short.
Fel-i-way is a pheromone product that can be used as it has a natural calming effect on cats. Telling them that 'everything is okay and good'. Masking scents and odors can be done with a spot of vanilla on the back of the shoulder-blades. I've never tried that, so wait for someone with more information about how that is done before you try that.
As for re-homing...it sounds like that may be best for him if you cannot resolve this current negative behavior, though I'd see if I could find him a home yourself where he could be an only-cat, if you can't get him into a reputable adoption program.
Best of luck,
PS...when we moved from CA to WA we brought our unsociable barn cat with us. The residence we had made arrangements to move into was sold out from under us just days before the moving truck came. We made some quick adjustments and had to move into a single-wide trailer at a trailerpark. When we arrived, the cats outside at that trailer park were very sickly-looking and I did not want to let Oscar out with them. So, he stayed in the front room while the other cats had the run of the trailer. Every evening I would put the group of cats into the Master Bedroom and let Oscar out of the front bedroom to socialize with us, play and exercise. We had to keep him in that manner for 7mo before we were able to find a suitable house to move into and he could return to being The Barn Cat...however he chose to become a Porch Cat and enjoyed sleeping in a box on a table so he could watch us inside the house. He never did adjust to being friendly with the other inside cats, or he'd have become an indoor cat.
Some cats are just meant to be only-cats.