As it says here on post its the 2016 challenge trend thats been going round social media since January.
Its just a bit of fun. It looks like its their dance from their wedding reception and yes as someone said they got married in 2018 but they started dating in 2016 hence they are being nostalgic about the year they started dating. So she hasn't got it wrong.
And as for that ageist comment that middle aged women dont that in terms of wrapping legs around their husband, well for one i still do it with mine. What's the problem? Why can't or shouldnt middle aged women do it? Some silly oh its so cringe if you do...its not harming anyone. Some people are more affectionate and loving and dont care showing it.
With so much crap going on its nice people are sharing content that's a bit of fun and affectionate.
I thought it was lovely and Harry was laughing and smiling at the end, didnt seem like he was forced to do it..maybe his face was just showing concentration on getting the moves done. Its not strictly come dancing where you have to be grinning all the way through it.