Continuity mistake: When we first see Kate and her parents at the restaurant there are only 2 empty chairs. Stewie then sits in the chair next to Kate. After Kate's parents ask what happened, we see a chair in between Stewie and Kate, but you can also see the edge of third empty chair. A plate and the wine filled glass also move.
Factual error: A TV announcer says "We now return to True Blood", indicating a return from a commercial break. True Blood airs on HBO, which is a premium network that does not show commercials.
Continuity mistake: When Brian is with Stewie asking for help, we see a set of blocks on the table, including a set of 3 stacked up. In the next shot, the 3 blocks vanish.
Chosen answer: It's a real song called "Elvira". Originally by Dallas Fraizer in '66, however, this version seems to be the Oak Ridge Boys cover version. However, the mega lesbians skip the verse and just sing the chorus after the opening line.
Bishop73