It is the simplest of gestures to show a loved one how you feel this Valentine's Day. But it seems there's more to a kiss than you might think.
For the direction you turn reveals much about your relationship, scientists say.
Couples who are in love tend to lean to the right, while parents kissing their children favour the left, they found.
Previous research has shown that around 80 per cent of romantic couples turn to the right when kissing, regardless of whether they were right or left handed.
The scientists wanted to see if this also applied to parental kissing. They compared 161 images of romantic kisses, between mothers and fathers, and 529 images of parents kissing sons or daughters.