Richie, Open to multiples at different parts of the night
Richie wore a well-fitted suit for the night, though once the ceremony was over his bow-tie would have been hanging loose from his neck and by the time he was singing karaoke he would have misplaced his jacket as well.
He spent the early parts of the evening greeting people, moving things around if they were in the way, and doing his best to make sure people were comfortable enough to have fun. He spent most of the time with a plate in his hand, grazing and occasionally offering things up to other people.
Once everyone had mostly arrived he started gathering up their family, directing them to the side room without giving away much about what would be going on in there. And once the ceremony was finished, he'd rejoin the party with a broad smile, hanging off of Eddie's arm for a while.
A few drinks in, Richie would have started on the karaoke, stepping up whenever it seemed like people were too nervous to jump in. He would have been the first at the mic with an enthusiastic rendition of Bohemian Rhapsody, figuring it would get people singing along and more comfortable. Then, throughout the night he would have ended up singing Eddie Baby while very dramatically acting like his husband wouldn't give in to him, and finally an almost impressive performance of I Believe in a Thing Called Love. He absolutely could not reach the high notes, but he tried every time. None of his singing was technically great, but he had a lot of fun with it and it was entertaining at the very least.
In between songs he would have drifted through the party, finding his way back to Eddie periodically but trying to interact with as many people as he could on his own too.