Girls ought to have some fun! This is what exactly Rihanna, 25 and her BFF Cara Delevingne, 20 did in Monte Carlo; taking off their clothes to bask in the sun. RiRi is on her way to Monte Carlo for her power packed performance and she certainly needed rejuvenation before beginning her 'Diamonds World Tour'.

Plunging in beach adventures, past this weekend, in Monaco, both the scintillating beauties slipped into neutral bikinis and cruised on a yacht. They also carried some water toys for their beguiling beach stint.

Rihanna showed of her famous assets in black, one-piece bikni in Monte Carlo. The swimsuit had the cut just in a right place, to reveal her cleavage and the tattoo.

And we think her lipwear was waterproof as it was untouched, the whole time she was tubing. A black revealing bikini with hot red lips, Rihanna surely knows how to rock the beach look

While Cara, pulled out an Aztec print bikini for the day and looked every bit of a super model. The top had two eyes peeping out to the world and the aztec print bottom hugged her at right places. Cara went sans make up, something we generally expect from the English celebrities. Her enviably toned mid-riff was on the show while she jet skied and we absolutely loved it.

It looks like both the girls had immense fun during their stay and it is a tough task to decide who stole the show at the beach. Well, RiRi you looked fantastic but we have to give this one to Cara for her nude look and an unusual choice of a swimsuit.

What do you think? Who shone out in the beach wear? Cara or Rihanna?