i am completely into the idea of two youngest siblings being planning a wedding and it being absolute mayhem for the rest of the people around them! i feel like butch would be calling him for sibling emotional support on a regular basis to whine/complain/scream into the void about what an absolute nightmare younger siblings are. so they could've done a big family thing at christmas in 2019, that could be when they'd met and their trauma bonding over eldest child/brother blues was immediate.