Zeraph

Also, a much lower chance than the above, but any blood born disease can be passed if you both have small cuts in your mouth. So there's 100s of major diseases that way...but really you probably risk worse in touching a handrail at the airport.

There are no actions without lasting consequence. But you gotta live your life, so don't let it worry you too much. And when thinking of risks vs reward, think of the rewards as the experience of love as a whole rather than just the pleasure of kissing one individual.