The Father, The Son, and The Holy Fonz - S4-E18
Continuity mistake: When Stewie is in the sterile glass cage, Lois is changing his diaper with rubber gloves built into one of the panels (like Homer Simpson's in the opening credits). In previous and subsequent shots, however, the panel is solid glass, with no gloves. (Series 4: The Father, The Son, and The Holy Fonz).
The Father, The Son, and The Holy Fonz - S4-E18
Continuity mistake: When Francis arrives, he changes from standing on the threshold to standing inside the house, even though he could not have moved between shots. (00:01:30)
The Father, The Son, and The Holy Fonz - S4-E18
Continuity mistake: When Francis is standing on a chair, nailing the crucifix above the door, the bottom of the crucifix overlaps onto the door frame, but when Francis comes down from the chair, the bottom of the crucifix is above the door frame.
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