The songbird posted the sizzling snap on Twitter.
A second image, also uploaded to the micro-blogging site, shows the 24-year-old hiding behind her hair as she soaks up the sun.
The star has been making some out-there fashion choices recently, including heading to the Australian premiere of her film Battleship in drab black overalls.
The usually-glamorous chart-topper looked totally out of place on the Sydney red carpet swamping her killer curves with the baggy onesie.
And she bombed just as spectacularly at a screening in Tokyo, Japan, sporting a bizarre blue outfit. The frumpy looks are a far cry from the skimpy get-up she dons for her raunchy music videos.
The singer recently told how she is desperate to bag her Mr Right – but can’t find a good man. She told Elle magazine: “I don’t think it has anything to do with being famous. There’s just a major drought out there.”
But she added that when the right fella comes along, she won’t let being a pop megastar stand in the way of love. She explained: “I just need to find the person who balances me out, because then things like my schedule won’t matter.
“I’ve done it before, so I know I can do it again.”
