Jon decided to make his Way downstairs, having to lift the dress to walk, otherwise risk tripping on it.
As he got downstairs he saw a pair of double doors, Jon cautiously opened them too see a large reception hall, people were all sitting facing away from him, but had turned to face him, It looked like A Wedding... and there he was at the entrance in a Wedding dress...
A man stood by the doors he just opened and took him by the arm, muttering something about how long it took to find a replacement.
Jon was terrified that they'd realize he was actually a boy, so he didn't make a scene and just walked with the man up the aisle, towards where a groom and a minister stood waiting.
Jon was allowed to walk the last few steps himself, up to and right in front of the groom, he was happy that the veil, atleast partially obscured his face, so that he wouldn't be recognized as a boy
The minister said his thing and when it came time, Jon was silent but managed to squeek out an "I do" not knowing what else to do.
The groom leaned over and lifted his veil, jon braced himself for the realization that his bride was a guy, but it never came, all that came was a kiss, Jon at first backed out of it, but again not wanting to draw any attention, just let it happen.
Afterwards Jon's husband took his hand and they ran out of the hall to the applause of the rest of the crowd, and he led him into a waiting limo outside...