Russell admits that the idea of being faithful is "weird" and he kept help but wonder about sex with other people.
He said on being a one-woman man: "It is a bit mad, especially when you're traveling around thinking, 'This is weird. Think of all the people I'm not having sex with. There they all are, look, not having sex!' But if you are getting married that's what happens and if this wasn't better then I wouldn't do it."
Speaking to Shortlist magazine Russell also spoke of how well he has bonded with Katy's religious parents Keith and Mary Hudson.
He added: "They're really lovely. I couldn't be happier with them and my choice of in-laws is almost better than my choice of wife. They're really, really cool people. They're funny, interesting, unusual people."
Do you think Russell will be able to stay faithful to Katy? Or do we have another Tiger/Jesse James on our hands? Seems like all he talks about these days is how hard it’s going to be to stay faithful.