Hyde would propose to her in the least romantic, momentous way possible. Like, over burgers one day in the parking lot of the Hub. They’d be sitting on the hood of the El Camino, she’d have just taken an enormous bite, and he’d casually let slip into conversation that that fixer-upper on Sherman was up for sale and maybe they should get married in the fall so they could save money for a down payment.
Jackie would go ballistic. First she’d throw her burger at him, then she’d throw herself at him. He’d laugh as they kissed.
It’s hard to tell who’d top whom in the outrageous planning department, Jackie or Mrs. Forman. Jackie would want calla lilies, and Kitty would insist on a string quartet, then Jackie would demand a six course banquet, and Kitty would be just over the moon for this three-tier buttercream cake she saw in the Piggly Wiggly with sugared roses and Grecian cake toppers that’d cost almost as much as the meal itself. Very quickly, Hyde would put his foot down. They could splurge on two things, he’d tell her, and that was it–any more than that, and they wouldn’t be able to afford the marriage license much less the wedding itself. After much wringing of hands, Jackie would decide on the dress (a simple, elegant number Pam helps her pick out) and her white doves.
Hyde would wear Red’s old navy suit. It would be a little long in the sleeves and tight around the chest, but Kitty would make it work.
The biggest logistical problem they’d encounter in the planning would be which side of the altar Kelso would stand on, Hyde’s or Jackie’s. In the end, he would stand on Hyde’s alongside him and Eric (because life-long best-friendship and bromance, etc.) but his official title in the program would be Jackie’s Man of Honor. Donna of course would be her Maid of Honor, as well as Hyde’s Best Chick, and Fez would be Jackie’s bridesman. (It’s at this point in the explanation that Red would get up and leave.) Fez and Donna would host the bridal shower because they both have keen, feminine instincts and Eric and Kelso would host the bachelor party because… well, they have weed and beer.
They’d get married in the chapel because That’s How Things Are Done and Jackie would insist. The reception, obviously, would be at the Formans, and Pam and Kitty would finally bond while making hor d’oeuvres. Pam would finally thank Kitty properly for looking out for Jackie (and forgive her for being a better mother), and Kitty would finally forgive Pam for abandoning her (and being far more glamorous than is remotely fair and decent). They’d sob all over each other at the wedding.
They’d honeymoon in Chicago. W.B. would put them up in some five-star hotel, and Jackie would drag Hyde around for days introducing him to literally anyone who would listen as her husband. He’d put up with it with only a moderate amount of eye-rolling it because he’s a good sport and he’d know there would be sexytimes in it for him in the end. Then, two weeks later, they’d return to Point Place, move into a shabby little bungalow with potential a few blocks from the Formans, and begin their life together. Not much would change, only the important bits. They’d still argue, but they’d be happy.
(She still likes being right.)