Continuity mistake: In the flashbacks to 1984, Peter and Lois are both 18, but in a previous episode, Lois says that she's two years younger than Peter.
Continuity mistake: When Peter goes back in time the first time, we see him and Cleveland slapping hands around the pool, we see that the pool is significantly shorter than in the scene where we first see Lois.
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