So Watson has been a bit of a dick recently. He blamed Mary's death on Sherlock AND got rather flirty with a woman on a bus for no reason.
But then towards the end of this week's episode "The Lying Detective", Watson admitted to Mary (who is technically no longer alive) that he had been flirting with another woman by text.
And then Watson apologised to Sherlock. Sherlock forgave him and hugged him a little bit.
Fans were, let's say, A LITTLE BIT EXCITED that Sherlock and Watson hugged in that moment.
Some people are really reading into it.
Really, really, really reading into it.
Then, in a dramatic twist at the very end, we found out that all of these characters were the same person...and Sherlock's sister.