Before the wedding, Mary and Missy Cooper are shown sitting in the front row, Raj is behind Mary, and Georgie is sitting in the 3rd row next to the side aisle. During the wedding, there is a close up of Georgie and Missy sitting next to each other in the front row.
When Amy asks Sheldon if he can sound Texan, he replies "I can. I will not." On occasion, Sheldon speaks with his native Texan accent, usually when he is around his family, when he is agitated like in The Vegas Renormalization (2009) (when responding to Penny's suggestion to come over and eat at her place) or drunk like in The Thanksgiving Decoupling (2013) (when slapping Amy on her behind and asking her to get a couple of beers).
When Missy first appeared in the show, in The Pork Chop Indeterminacy (2008), the only one of the guys she shows interest in is Raj, but that fell through when Raj couldn't speak to her. Now that she's single again and Raj can now speak to women, she appears to have completely forgotten her interest in him, even though he reacts positively to the news she's divorced.
Sheldon indicates that if he ever needs a kidney transplant, they should get it from his sister Missy. However, Missy is not an identical twin to Sheldon and is not as likely to be a match as his brother Georgie because she is not the same sex as Sheldon.
Luke actually wasn't on the Wookie planet Kashyyyk in the Star Wars Holiday Special. His only scene involved talking to Malla via teleconference from his workshop where he and R2D2 were working on the X-Wing. As for not knowing Chewbacca had a wife, that could be stemming from either his denial of or his inability to remember being in the Holiday Special due to either the negative reception it got or because he was rumored to be on drugs when he did it and literally didn't remember doing it.
Or maybe in real life he does remember being on that show but the writers wrote for the script for this show that he doesn't. It's sometimes the case that actors don't remember being on certain shows, or the plots of those shows, for various reasons and this parodies that situation.
Or maybe in real life he does remember being on that show but the writers wrote for the script for this show that he doesn't. It's sometimes the case that actors don't remember being on certain shows, or the plots of those shows, for various reasons and this parodies that situation.
Barry Kripke sings 'At Last' as Sheldon and Amy walk down the aisle after the ceremony. In an earlier episode, Kripke demanded he would be allowed to sing at their wedding in order for him to move his birthday party so the couple could have their wedding at the society. He then demanded he could sing 'Volare', not 'At Last'.