REN enthusiasts have been blessed with some absolute gems of fanfics that I've adopted as my own personal canon on this topic, making me very fond of Emma learning about weddings from the books' in Grace Field's library and immediately thinking of course she and her two best friends should have one. They've been inseparable since she arrived at the house, and she can't imagine her days without either of them, so the only solution is for all three of them to marry each other.
I adore the way Ray's chapter of Between Your Fingers, Between the Lines by honeynpeaches opens when he's around six years old and Emma dropping flower crowns on the boys' heads, declaring they'll be wed that very day.
Everything about this little snapshot is perfect. Emma walking onto the scene framed in the imagery of a halo. Norman being an adorably smitten baby going on the fritz for the first few minutes of the entire conversation. Ray being an amalgam of emotions held together with a rubber band on the verge of snapping. His reaction to Emma's quick and casual defiance of whatever she deems arbitrary is a wonderful blend of comedic and heartbreaking. The pure frustration at her flippancy born out of a deep and endearing love that trumps his fear of the whatever consequences result from confronting Isabella.
But he sees how Emma and Norman smile, and he can’t deny them. He’s never been able to. Not really. Not when it matters most…He’d give anything for them, and he already knows it.
Down to the more minute gestures of Norman moving to calm Ray after he's calmed himself down in a familiar, reassuring rhythm
(Chapter 28 Bonus Comic about Chapter 14's flashback)
with the gentle placement of his hand over the other boy's, and Emma taking his other hand to move close to her heart to subconsciously convey how much it would mean to her to be able to reify their bond through such a ceremony, even if it's only pretend.
For how their play wedding goes, I love what @carnivorouswillgraham does in w.a.m.s. that I've already gushed about here
But aaah do I love the idea of the music box Emma received from Isabella as her gift being the musical accompaniment to their ceremony.
(Mystic Code Book Chapter 1 Q&A)
In addition to them just all being adorable little babies enjoying the chance to recreate such an important ceremony between all three of them, even if just pretend.
Baby Ray going through an existential crisis but still trying to be present for his bffs/soon-to-be spouses and genuinely finding some solace in these moments with them that will solidify his resolve to confront Isabella in just a few days.
Just continue to fucking gut me.
For adulthood, I'm half and half of whether they'd have one, but if they do and Emma regains her memories, I imagine it playing out very similar to how it does in @salsae's to have and to hold, which I've gushed about a bit already here.
All of their friends and family gathered together at one of their homes or whichever quiet venue could accommodate such a large gathering, some of their siblings walking them down the aisle as Nat plays the piano, Emma in relaxed summer attire befitting or her kind and free spirit, incorporating the paper cups as part of the vows and the galaxying braining of turning it into a REN thing rather than solely an NE one, the trio taking turns crying out of joy (because ofc they can't all cry at the same time), Ray somehow getting roped into catering his own fucking wedding…it all comes together in such a beautifully brilliant way that I can't really think of anything to be altered except Alex walking Emma down the aisle.
If Emma doesn't regain her memories, I'd still imagine something similar playing out with it being a lowkey event in someone's backyard, but there's less chance of Ray prioritizing getting NE together separate from him (for a while) because in his mind they're forever classified as a matching set that he's not a part of
(2020 Exhibition Interview)
And more of a chance of them officially getting together as a trio to start off due to both the search for Emma leading Norman and Ray to grow closer in her absence (while holding off on progressing further in a relationship until reunited with their third) and then all three of them navigating her memory loss.