Me and my boyfriend are wanting to get married..he’s never been intimate with anyone else and I’m afraid that will make him curious in the future. Do you think it’s possible for him to never want to be with anyone else?

Of course it is. Just because he has a penis doesn't automatically make him a sex crazed horn dog! You can easily be all he ever wants and needs. I understand your concern but please give him the benefit of the doubt first before you start thinking that way.