Irene the matchmaker (johnlock)

Prologue

After Irene -with her girlfriend, Kate- escapes Jim Moriarty's clutches to America with Sherlock's help, she has no more reason to try to prevent Sherlock and John's inevitable relationship.
Because really, they were so obvious. It was almost painful to watch them dancing around each other, she almost wanted to disobey Moriarty's orders and get the two of them together.
She had, in fact, slipped up a few times and almost let Sherlock know how John felt, luckily for her, Sherlock was an idiot, sometimes.
So now that she's free to do as she likes, she's set on putting the two of them together.
Which she attempts by blowing up poor Sherlock's phone with advice on how to express his feelings towards John.
Unfortunately, during that time, Sherlock was under stress due to Moriarty, so he could do nothing until Jim was out of the way.
So then the fall happens, and Irene keeps texting Sherlock throughout his painful expeditions to eradicate Moriarty's network.
Honestly, it's nice for Sherlock, having someone to talk to about the feelings he has for John, mostly because she already knew about them.
So when Sherlock gets back, he's fairly ready to take Irene's advice.
However, something beyond what either of them would have predicted was one Mary Morstan, or well, whatever her name was.
So Sherlock mostly abandons hope again.
He gets asked to be best man, and as surprised as he is that John cares for him at all despite what he did and considers him his best friend, he doesn't feel much better about his chances.
Irene is over the moon, of course, because she was right!!!
And all through the wedding preparations, Irene is imploring him to just talk to John because she just knows that he would drop the whole thing if he knew how Sherlock felt.
So Sherlock gives one last try at the stag night, and it almost happens...
But it doesn't.
So Sherlock pours his heart out in what was the gayest best man's speech in the history of the universe and John is so close to realizing Sherlock feelings.
But well, John's an idiot and he's got a pregnant wife to think about.
Plus, if Sherlock felt that way, he would have said something, right?
Sherlock is disheartened, and Irene offers her condolences, even though she's still sure that John would choose Sherlock over Mary if he just knew.
Then Mary tries to kill Sherlock and John is furious and Irene kinda wants to come over there and tear Mary's head off because she's invested a lot of time into getting these saps together and neither of them are allowed to die before that happens.
But Sherlock made a vow to protect the love of his life and the woman he chose, so he gets them back together so he can protect them both.
And things don't go quite to plan, but after a nasty overdose and a threat that may or may not be Moriarty, Sherlock is back and going to keep the Watsons safe.
Then, in a rather dramatic turn off events, Mary gets killed and John is once again a free man.
John is struggling with it, mad at himself for not loving her like he loves Sherlock and almost using that woman on the bus as an outlet to his desires for his former flatmate. And Sherlock feels guilty, thinking that if he didn't love John, he would have noticed the signs of Mary being an assassin sooner and been able to help her faster and would have not put her in the danger that got her killed.
Meanwhile Irene the matchmaker is back stronger than ever, and although Sherlock appreciates her advice, really, he's sure John doesn't feel that way anymore especially now that he's caused the death of his wife.
Irene, of course, knows what's really going on, but Sherlock is really an idiot with sentiment, so he's clueless.
Meanwhile poor jealous John, finally free from the life he'd forced himself to have, still thinks Sherlock is interested in Irene when he discovers that she's alive and been in contact. But he never was very observant.
And Irene is getting tired of this game the three of them play where John and Sherlock dance around each other while she tries to get them to stop being coward and just say something, but she's determined to win before she quits.
And she knows she can, she just has to figure out how.