I think the issue of kids is a big one here. I can see someone converting in name only, or converting for the cultural aspects, etc., to be with someone, I guess. But then there's the issue of kids. Will you raise the kids to learn both "sides" of things, and then let them choose? Will the one person lie when they ask her what he/she believes in? Does the converting person really think it's OK for his/her kids to believe something that he/she doesn't believe?