Singer Britney Spears has reportedly put her backing dancers on a sex ban.

According to a source, the 34-year-old, who has returned to her `Piece of Me` residency here, is so obsessed with impressing fans with her dance moves, infectious music and dazzling costumes that she's put her staff on a strict routine, reports femalefirst.co.uk.

`Britney expects the same level of commitment from her dancers as she does herself, and so any distractions like sex and booze are off-limits. Anyone who doesn't play by the rules is out. it's as simple as that,` Heat magazine quoted the source as saying.