Klaus starts to play Etta James "At Last" when Stan brings home the second goldfish.
Technically, Stan and Francine haven't been married for twenty years because in "When a Stan Loves a Woman" they were temporarily divorced. Also Joanna, the woman Stan married during the episode was one of the guests seen at the wedding at Pizza Overlord.
Francine is a Libra as her birthday is September 26th.
When Stan is making his getaway at the wedding, he trips a harp that produces the Hanna-Barbera "Kabong" sound effect.