Mirror - Kissing may seem like a relatively straightforward way of passing the time, but it's can also be a health and safety minefield.
Much in the same way licking the floor of a public bus comes with its pitfalls, so does puckering up to someone else.
There are, of course, the obvious risks.
You should probably try to contain your ardour if the object of your affection has a cold sore, or if their feeling under the weather.
But there are a whole raft of nasties lurking in other people's mouths, and some unpleasant (and sometimes dangerous) consequences to kissing, as Kelly Reynolds, PhD, microbiologist at the University of Arizona's Zuckerman College of Public Health revealed to Cosmopolitan .
Meningitis and glandular fever:
According to Dr Reynolds, these are two of the most frequently transmitted pathogens via kissing.
Glandular fever is still referred to as the "kissing disease", so high is the risk of contagion. Its symptoms - often long-lasting - include extreme fatigue.
With meningitis , "the inflammation of the membranes surrounding your brain and spinal cord, can last up to 10 days, sometimes causing permanent and even life-threatening damage."
"Neither conditions are remotely desirable."
Sex Education may seem like a dim and distant memory, but as a refresher, microbes that cause gonorrhea, syphilis, herpes, and HPV can be transmitted through saliva.
What makes this worse is that these infections can often be asymptomatic, meaning they get passed on easily and continuously between partners through just kissing.
With dental plaque and cavities harbouring bacteria aplenty, Reynolds says the latter should be considered as being contagious.
Don't let a partner's minty fresh breath fool you either, as anyone can have an oral infection, regardless of how pleasant their breath smells.
A Swedish survey recently revealed how 12 per cent of people with a food allergy will kiss someone who triggers a reaction owing to the food they've eaten.
The likelihood of this is greater is your partner has just eaten that item of food, but it also depends on the severity of the allergy, which can include hives, facial swelling, shortness of breath, and vomiting that can occur within minutes of exposure.
It's not the most romantic conversation in the world, but it might be advisable to bring any allergies to your partner's attention.