I am going to inform my DH that the burden of proof is on the nonsensical party, I like that. Thanks. Of course, he thinks I'm being nonsensical.
And from the comments section of the Mental Floss article, none other than Frank Arietta agrees with him: "X = hug, (make an X with your arms like a hug or greeting from an oompa loompa) O = kiss (make an O with your lips... like giving a kiss...) I always knew that is was hugs and kisses, not kisses and hugs. What's written above is just nonsense. Religious history? Really, guys?"
So I might need to print that article out but not show him the comments section, in order to put this to bed.
And Frank sums up DH's arguments - according to him, it's self-evident that O = kiss, because when you kiss your lips form an O, and X = hug, because when you put your arms out for a hug, you make a giant X.
To which I say, putting your arms out as wide as you can certainly looks like a giant X, but to me is actually an anti-hug posture.