The 23-year-old singer met the Irish actor on The Graham Norton Show in 2010 and according to gossip, they swapped numbers and have been exchanging saucy texts ever since.
But Rihanna said that it couldn't be further from the truth.
'He probably thinks I'm starting all these crazy rumours,' she told Rolling Stone. 'We don't even have each other's numbers. I wish. He's smoking.
'I'm not dating. I'm not sexing, I'm not even sexting. It's on complete nil. I haven't gotten a d**k picture in a long time. I think people are a little afraid. It can turn out bad.'