Continuity mistake: After the Robert Redford clip, when it cuts to the Griffins walking toward Doug's house, in this exterior shot (and a previous exterior shot) the front door is located between one window and the garage, but in the following interior shots there's a window on both the left and right side of the front door. (00:14:20)
Continuity mistake: After the LASIK surgery Lois has bandages covering her eyes, and the pairs of crisscrossed tape switch their over-under positions within the same shot.
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