Parents kissing their children on the lips has always been a contentious issue. This is particularly the case in the modern world where people are all too aware of adults abusing their position of power with children and using it as an opportunity to exploit them.

For the majority of people, however, kissing their children feels like the most natural thing in the world, especially when they are babies. But it turns out that showing your child affection, even if it makes them feel loved, could be doing them more harm than good.

The issue of parents kissing their children most recently hit the headlines when Tom Brady was filmed kissing his 11-year-old son last month. It divided viewers of Tom vs. Time, with some people labeling it as nothing more than innocent affection and others slamming it as disturbing.

Now, Dr. Michael Chong, a pediatric dental specialist from the Gold Coast, Australia, has revealed that a parent kissing their child on the lips could also pose a serious health risk. This is because they could pass on the bacteria which cause tooth decay through mouth-to-mouth contact.

“The damaging and non-damaging bacteria is spread through the transfer of saliva, and is most likely to pass to infants around or even before the time of baby teeth erupting,” Chong told The Sunday Mail.