Kissing at the conclusion of a wedding ceremony can be traced to ancient Roman tradition where a kiss was used to sign contract.
Two-thirds of us tilt our heads to the right when we kiss, and it’s not correlated with right-handedness.
A man is far more likely to prefer sloppy tongue kisses than a woman. The added testosterone from his saliva may serve to enhance her libido over time.
The world record longest kiss belongs to Nikola Matovic and Kristina Reinhart (both German) who kissed for 32 hr 7 min 14 sec in Hamburg on Feb 13th-14th, 2009.
Humans aren't the only animals that kiss. Great apes press their lips together to express excitement, affection, or reconciliation.