I asked a Hispanophone friend and was told that "unión convivencial" and "unión civil" are both terms for civil union in Argentinian law. Presumably Edu can confirm or disconfirm this. My guess given this is that what Francis was doing here was confirming the open secret that this was his position during Argentina's SSM debate in 2009-2010, and saying that he still feels that was the correct approach.
I actually had no idea about this so I had to search for a bit. What I found is that "union convivencial" and "union civil" are actually slightly different things and obviously different from full fledged marriage.
The main difference between the 2 unions and marriage is that if you are married and die, your spouse will automatically inherit everything you have, while in the unions you have to specifically make a will to that effect.
Apparently the "unión convivencial" doesn't require it to be formally registered as the other two options (with witnesses and everything) which means that you can end the relationship just by saying so, no need for anyone else to intervene.
The "union civil" requires you to do some legal stuff to end the relationship but nothing major and marriage of course involes the courts.
Still not sure about the details and frakly I don't care to search for it now since it's 5 AM here and I'm a bit drunk lol but I'll ask my dad later if he can shed some more light.
