I thought you all might find this interesting to think about in terms of world-building, especially when writing fantasy or science fiction romance: "We looked at 168 cultures and found couples kissing in only 46 percent of them."
https://www.sapiens.org/culture/is-romantic-kissing-a-human-universal/
https://www.sapiens.org/culture/is-romantic-kissing-a-human-universal/