Well, we have a cat that I agreed to foster, oh 6 years ago or so. One day dh (who did not want anymore animals) looked at the cat sound asleep at his feet and said "this cat isn't leaving is he?"
I had never planned for him to.
Seriously though, I DON'T advocate that unless you know your hubby well enough that he won't still push the issue. This was after many years of marriage and I knew mine would cave once kitty was around for awhile. I wouldn't have risked it if I thought I'd have to find kitty a home down the road. It's not fair to animals to move them around too much. If it's not going to work with your hubby right now, let the new one go to a family who all want him and will keep him.