We generally attribute discoveries to whoever documented it first. It’s almost laughable to attribute it to the French based on a kissing style that was widespread there in 1923. Surely people were doing it before then. Yet, the Americans and British found it so unique they referred to it as French kissing.
Perhaps it was common before ancient India, but then the question is, why didn’t the ancient Babylonians, Egyptians, Chinese, Romans, and Greek document on it then?
https://streamable.com/36e2vk