This was one of those movies I looked up Netflix because I'd heard the title mentioned in another context. I ended up watching the whole thing, even had to hit pause to go and get tissues. Bridegroom is so honest, so strong.
If you need to show someone why marriage should be for everyone - gay or straight - show them Bridegroom.
Sweden has had gay marriage since 2009. My mother is a Vicar in the Swedish Church and she married a gay couple a few months ago. Her only worry was that she would slip and say "husband and wife" instead of "husband and husband".
If you want to know more about what it's like to be gay around the world, Stephen Fry made an excellent two-part documentary called "Out There". I learned a lot and I admire the way he conducts interviews so calm and so well-researched.
You can find it on YouTube. http://youtu.be/ZAPfPVD8pRE