If you're a fan of cheesy '90s pop, be prepared for the following video.

Britney Spears, as you may know, is still in residency in Las Vegas with her 'Piece of Me' show - and is even rumoured to be extending her run by a further two years.

Meanwhile, her fellow popsters Backstreet Boys recently began their own residency in Sin City, and it seems that one of the boy/man band found his way onto Britney's stage the other night.

Howie D from BSB made an appearance during her song 'Freakshow', basically taking on the 'sex slave' role that an audience member usually would for the routine - and he even got a signed t-shirt for his troubles.

Watch it below: 


Leave it to @BritneySpears to bring out the freakshow in Howie D! What happens in Vegas... #pieceofme #pieceofhowie #bsbvegas

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