I am about to get married to an INFp. It works for us. However we are both late twenties, even a year ago I dont think either one of us would be ready for marriage. Timing was everything.
I do find the question strange when anyone asks "do you want to get married?" when I was single. To me, the question is way backwards and I never really knew what to say because to me, the question would be "do you want to find someone you would like to get married to?" rather than just have a marriage just for the sake of it.
IMO, I have seen way too many people just get married because they wanted to without thinking things all the way through. So I guess Im a bit more pickier than most as I would rather be single any day than just get married for the hell of it.