Oh, hello there conscious mind. Good of you to notice that the things subconscious has been screaming about for ages are Lois Lowry vibes. You two should talk more.
She's a sin-eater. Satsuko is what she uses as a sink.
I will observe that Jiraiya and Mari never had a
wedding ceremony, even though they were '
married' in the eyes of the law.
This is mostly be a social and political issue. Getting married without respecting Leaf tradition and getting formal blessing would be an enormous hit to the Goeketsu barbarians in particular.
-so, create special circumstances which nobody can argue don't justify an exception. Get Asuma to formalize the alliances with Sand and Mist and use the wedding as an appropriately representational international celebration of it. Sand is already begging, and trouble in Tea might well indicate that the inevitable conflict between Lightning and Mist over Mist's control of their only land trade route is beginning to boil over. Preeeeety sure that the clan will bow to the pressure instead of angering three Kages while cutting themselves out of the most notable ceremony in living memory. If they don't, well, destination wedding. Mist is supposed to be nice this time of year. I would recommend inviting Hinata to give a toast, but I suspect that she'll have to beg it off due to having a frog in her throat.
Oh, might also want to mention this to Tsunade. She seems to approve of Noburi, and rumor has it that she has a really big thing about weddings. Pipsqueak clan might think twice about publicly irritating the most important clan and most beloved person in Leaf history.
"Aunt Sunny! We're getting married! It's going to be a huge party with an open bar and afterwards everybody's going to go play games at our private tavern-slash-casino!"
*NEXT DAY*
"Ummm... I'm really sorry, but we have to reschedule. Everything's kinda on pause right now because the Hagoromo say they won't officiate for anybody in the clan. Apparently, we offended tradition and decorum because Keiko likes girls. Oddly enough, they're still fine with the Nara."
If we're really, really angry, mention the situation and their reasoning to Keiko, Snowflake, and Ami.