A reggae-pop and R&B track, "Slumber Party" features brass, marimba, "syncopated synths", percussion and a horn section in its instrumentation.
Lyrically, the song is defined as an ode to fornication and making sex tapes, where Spears uses double entendre, while evoking one-night stands, the ritual of sleepovers with friends and the teenage game of seven minutes in heaven.
The song appeared on the national charts in countries including Canada, Spain, Scotland and the United States, where it debuted and peaked at number 86 on the Billboard Hot 100, and topped the Dance Club Songs chart after several weeks.
For Alex Macpherson of The Guardian, the song "is reminiscent of Spears' 2003 album, 'In the Zone'."
Neil McCormick of The Daily Telegraph called it "effervescently catchy" and "a gem of slinky TLC."