I'll just add a general blanket statement here since you haven't really provided us with the useable info needed to give any real advice.
What you really should be asking is why it bugs you, or why they think they can display such intolerace. Sure they're your relatives but your obligations really end at your personal relationship with them and any shortcommings in the way they view the world shouldn't bug you. But if it still does, it seems the only way to reduce the impact of their opinions on your personal life is to make sure they know to trust you with decisions you make by making more of the important ones on your own, but first make it known that it bugs you, maybe they're under the impression that you too subscribe to the same narrowminded views that they do.