It's hard not to envision your life with someone like Mitsuya, especially after going through so many failed relationships, when you find something so good for yourself is natural that you'd never want to let go, despite it seeming too good to be true, it's a reality, for you.
Not only he's a genuine sweetheart, but he's also a great cook, good with kids, knows how to sew, and clean a house like nobody else, he's also very responsible and respectful, and likely one of your best choices in life was to date him.
So likely as he's good at sewing, he had asked what you'd like in a wedding dress, and you gave him a few ideas on what you'd like on it, even made a sketch though it wasn't nearly as good as his, so he made the adjusts and eventually had the final product.
There is this whole thing about bad luck, that the groom shouldn't see their dress before, but the two of you skipped that part.
“Hold it, yeah here” He says guiding your hands to hold the front part of the dress, as he adjusts it.
“I'm going to pin up a few parts, stay put so that I don't end up poking you” He plants a small kiss to your shoulder, the dress being an off the shoulder style did help, he made sure to follow your descriptions even the fabric of choice.
“You look gorgeous” He rests his chin on your shoulder, a hand lingering on your waist as you stand in front of the mirror. “There's no such thing as bad luck if we see each other or our attires before the wedding, you are my luck” he smooches your cheek before getting his attention back to the dress before him.