Yeah, I didn't see any mention of the wife showing interest in poly, in general, nor in you, specifically, just that he thought it'd be good and you wanted to be with him and BAM! the three of you are together. For her to get an instant girlfriend and housemate (essentially) without having any interest in such previously and no time to consider it and embrace it as something she wants...well, I don't think y'all were very considerate of her.
When speaking of various forms of non-monogamy...it ain't poly if you're just fucking around.
While polyamory, open relationships, and swinging are all distinctly different approaches to non-monogamy, they are not mutually exlusive. Folks can, and some do, engage in more than one of them at a time--and it's all good.