Sherlock hasn't subbed consensually since before his fake suicide.
John has always thought Sherlock to be a Dom because well duh. And now that Sherlock is back, recovering from his high, it becomes obvious how unstable and unable Sherlock is to stay grounded.
John realises Sherlock needs to sub and he convinces Sherlock to let him. Sherlock agrees because he trusts John but the past few years of trauma and the need for him to hold himself together just makes it impossible for Sherlock to stop being so tense. John cannot get Sherlock to relax enough to make their sessions comfortable and they both work through the trauma and tension.
John/Sherlock Dom/sub Sherlock has been tense since he left
John has always thought Sherlock to be a Dom because well duh. And now that Sherlock is back, recovering from his high, it becomes obvious how unstable and unable Sherlock is to stay grounded.
John realises Sherlock needs to sub and he convinces Sherlock to let him. Sherlock agrees because he trusts John but the past few years of trauma and the need for him to hold himself together just makes it impossible for Sherlock to stop being so tense. John cannot get Sherlock to relax enough to make their sessions comfortable and they both work through the trauma and tension.