Sheldon for the second time gets upset that butterflies might be released at a wedding and he calls them "airborne worms". Penny mentioned it when she and Leonard were planning their wedding in The Commitment Determination (2015).
Sheldon mentions the new Star Wars movie is coming out, referring to Star Wars: Episode VIII - The Last Jedi (2017).
Title reference: Raj believes that Howard is eroding his confidence with his incessant pranking.
Sheldon wants his wedding vows to be in Klingon. In The Countdown Reflection (2012), he tried to do Howard and Bernadette's wedding speech in Klingon, and when told to do it in English, he mentioned that Klingon loses something in translation.
Brian George (Dr V.M. Koothrappali) and Mayim Bialik (Amy Farrah Fowler) previously worked together on the Blossom (1990) episode, Oh, Baby (1994) as Shakir and Blossom respectively.