Their romance comes after Hassan was previously spotted looking affectionate with supermodel Naomi Campbell in July 2016 at the British Summer Time Festival in London.
Rihanna, meanwhile, reportedly called it quits with rapper Drake, 30, in October 2016 after an on-off romance.
Dating is a stage of romantic relationships in humans whereby two people meet socially with the aim of each assessing the other's suitability as a prospective partner in an intimate relationship or marriage.
It is a form of courtship, consisting of social activities done by the couple, either alone or with others.
However, one particularity of the human species is that pair bonds are often formed without necessarily having the intention of reproduction.