This is a song from Gwen Stefani's 2004 debut album Love.Angle.Music.Baby. The song is set back in the 1950's and talks about her going on a date with her boyfriend and losing her virginity. "Bubble Pop Electric", is the sexual metaphor.
The chorus goes "Tonight, I'm gonna give you all my love in the back seat....Bubble, Pop, Electric". (Back seat, being the back seat of her boyfriend's car, not her butthole.)
Bubble - foreplay and build to climax.
Pop - "popping" her cherry for the first time.
Electric - climaxing, and the connection between both lovers.
"Last night, my boyfriend popped my cherry. It was like Bubble Pop Electric!"
To get banged in the butt.
Ref; Gwen Stefani song Bubble Pop Electric "Love in the back seat"
"Last night my girlfriend let me bubble pop electric all night"