The raunchy singer apparently took to the mic at Whisky Mint in London's Mayfair, where she was celebrating brother Rorrey's 22nd birthday on Sunday, and offered up some pearls of wisdom for her fellow revellers.
'I left home at 16 and had to learn to look after myself,' she said, according to The Sun.
'Always use a condom.'
Fifteen bottles of champagne and six bottles of vodka later, the Bajan star is said to have herded everyone back to her suite at The Savoy hotel where she gave her brother a party to remember.
'Rihanna is the best big sister,' said a source.
'She sorted for all these girls to accompany her brother back to her hotel, along with his friends too.
'They had a great time and she treated them like kings.'