A few weeks after Discord & Screwball's Engagement, they have everything set up for the wedding, they decided to hold the wedding within the Chaotic Kingdom Amusement Park, advertising it as a big & special event that no one would want to miss out on, this allows it so that everyone could attend the wedding without using up very much of their own time.
It was being held in a huge empty lot meant for Large Party Reservations, they had big tents set up for dressing rooms among other purposes, there were lots of Discord & Screwball clones working as the staff, and they were specially dressed so that everyone could tell that they were just magically forged copies and not the Originals who were getting married.
Princess Celestia herself agreed to be their Marriage Officiant, the Mane 6 agreed to be Screwball's Bridesmaids, with Princess Luna as the Maid of Honor, and Spike as the Best Man, and the CMC were the Flower-Girls, many ponies & creatures from all over Equestria & beyond showed up for this wedding, including Prince Shining Armor & Princess Cadence(who have only been married a few short months now), and Discord's old friend The (FiM)Smooze, Screwball's Parents were reluctantly there as well(if only to see their daughter on her big day).
The Mane 6 were in the Bride's Tent with Screwball, helping her with preparations, Screwball then did the old 'unzip yourself to reveal you were wearing a full body disguise' cartoon gag to reveal herself wearing her own bridal gown, which was like any other bridal gown except for the fact that it was filled with a bunch of random colors, design styles & patterns that all clashed like crazy, Screwball then asks the Mane 6 how she looked.
Rarity acted like she was going to be sick just from the sight of such a mixed-up designed outfit and simply says "You look beautiful Darling".
Applejack adds in "Yeah if you were going for Something an Art Museum Sneezed Out".
Rarity responds "Applejack!".
But then Screwball blushes & replies "Aw Thanks, That's so Sweet of you to say".
Suddenly Spike barges into the Bridal Tent looking like he's panicking over something, Twilight asks Spike if something is wrong, Spike informs the Mane 6 that Discord is getting Cold Feet & thinking about calling the wedding off, The Mane 6 are shocked but don't want Screwball to worry about this, so Fluttershy volunteers to talk to him while the others keep Screwball distracted.
When Fluttershy spoke with Discord she reminds him that This whole thing was his idea in the first place, and that he was the one who proposed to Screwball because he didn't want her to literally spend all eternity alone like he did for so long, Discord is aware of all of that but starts acting nervous & talking without actually saying anything.
Fluttershy asks if he's afraid, Discord replies by getting boastful & bragging about how awesome he is, many of the incredible things he's done, and a bunch of the horrible monsters & wicked villains he's face & defeated, then he says "So what have I got to be afraid of?! After all I'm only getting M-M-M(stuttering uncontrollably)", and he ends up getting nervous anyways.
Fluttershy then asks Discord to remind him of how he really feels about Screwball, Discord then says "What kind of Question is THAT? She was the first being in Ages that saw me as a Person with a Personality, instead of some Beastly Monstrosity that needed to be contained, or a Plague that needed to be cured, she figured out what my real problem was, and set me on a better path where I was able to find acceptance in a society that greatly misunderstood me, I wouldn't even be here right now if it weren't for her, she makes me feel whole, like whatever void I had in my heart for all these millennia was filled the day I met her, I feel like living forever & being chaotic would all be worthless & pointless without her by my side, I would give anything, Do anything, to have her with me for all eternity & make her happy".
Fluttershy then assertively asks "Really?".
Discord replies "Yes!".
Fluttershy then grabs Discord by the face and looks him dead in the eyes while saying "Then what are you stalling for, get out there and show that Mare that she's the Luckiest *Censored* Alive, because she'll have You as her Husband!".
That definitely snapped Discord out of his pre-wedding jitters, he then puts on his wedding attire which is in a similar fashion to Screwball's wedding attire, and the wedding proceeds as planned.
The ceremony begins much like you'd expect a wedding to, aside from a few random bursts of silliness out of Discord & Screwball.
When the ring bearer brought forth the wedding rings(which were made for fingers), Screwball took her tail, used the curls in her tail's hair like fingers, made it look as if it was a hand with a thumb sticking out, then blew into her tail, then both of her front hooves swelled up until they popped into a pair of human hands, She & Discord then place the rings on each other's fingers, Screwball then does that same trick with her tail, but this time she sucks on it, which causes her hands to get sucked back into hooves, and she's keeping her wedding ring inside of her hoof for safe keeping.
Finally Celestia pronounces Discord & Screwball, Husband and Wife, then informs Discord that he may now kiss the bride, and their marriage is sealed with a kiss.
Later we see the wedding party, which had good food, awesome music by DJ PON3, and all sorts of dancing.
Upon reaching the wedding carriage, Screwball throws the bouquet, then Rarity frantically tries to catch it, but when she does, she finds out that it's not a bouquet of Flowers, but a bouquet of multicolored Fishes, which totally grosses her out, the King & Queen of Chaos manage to see Rarity's reaction and get a good laugh out of it before closing the carriage door.
Then the horseless carriage has a giant set of wings sprout out of the wheels, then the carriage starts flapping said wings & takes to the skies, then it starts to glow, then does that 'warp into hyperspace' thing.
And while all of the Copies helped make sure everyone got home safely and took care of the clean-up.
The Original Discord & Screwball spent their honeymoon on a small planet located somewhere in the Draconis Nebula, the planet was teaming with life like a rain-forest, and had a phenomenal multicolored cosmic formation in the sky, this place was so beautiful that it made a Full Moon lit Paris France look like some redneck's uncleaned outhouse, in other words they had a wonderfully romantic time.