R&B star Rihanna is unfazed by rumours alleging she's a closet bisexual after saucy photos surfaced online depicting the singer groping a female friend.

The Umbrella beauty famously dated fellow pop star Chris Brown for two years, before their relationship came crashing to an end when he beat her up in February.

She has repeatedly denied reports romantically linking her to rapper Drake and actor Tristan Wilds, declaring she was not yet ready to date.

But temporarily swearing off men has only reignited allegations she's secretly harbouring a love for women, which have been circulating the internet since images of Rihanna getting wild with pals surfaced online in January.

One picture showed Rihanna fondling the breasts of a gal pal - but the 21 year old has laughed off the saucy snap, insisting she's just a big flirt who appreciates the female form.

She tells New York DJ Angie Martinez, "There are tons of them (photos of her grabbing boobs) online! I don't have a lot so anytime I see a good rack (pair of breasts), I grab 'em. Women are beautiful. I'm not into them, but they're beautiful. Girls just wanna have fun!"