A frequent theme in such fanfiction is the idea of transformation. The kiss between John and Sherlock can be seen as a moment that changes the entire dynamic of their relationship. It can also lead to changes in how they view themselves and their place in each other's lives. Additionally, the theme of vulnerability is quite common. The act of kissing makes them both vulnerable to each other in ways they haven't been before.
I'm not sure of a specific 'John kisses Sherlock fanfiction' title off the top of my head, but you can try looking on Archive of Our Own (AO3). It has a huge collection of fanfictions related to this pairing. You can search for the 'John/Sherlock' relationship tag and then narrow it down by looking for fics that involve a kiss between them. There are many talented authors on that platform who write engaging stories about their relationship.
The chemistry between Sherlock and Molly in the original series has a lot of potential that wasn't fully explored. Fanfiction allows fans to expand on that. The idea of them kissing is exciting as it's a turning point in their relationship, from just being colleagues or friends to something more intimate.
There are many interesting fanfictions about Vampire John and Sherlock. One common theme could be how Sherlock, with his brilliant deductive skills, discovers John's vampire nature. It might involve a lot of mystery-solving around John's condition and how they navigate their relationship in the face of this new revelation.
The appeal lies in the unique twist it gives to the classic characters. It combines the mystery-solving aspect of the original Sherlock Holmes concept with the allure of the supernatural. Vampire John adds an element of danger and mystery.
In many Sherlock/John fanfictions, their care for a baby can be quite heart - warming. Sometimes it's a case - related situation where they end up taking care of an orphaned baby during an investigation. This often shows a softer side of their characters, especially Sherlock, who might seem initially clueless but gradually grows attached.
In many Sherlock/John fanfictions, Sherlock's actions towards John show deep affection. For example, he often goes out of his way to protect John from danger. He might put himself in harm's way just to keep John safe, which can be seen as a sign of love. Also, his jealousy when John pays attention to others can be an indication. In some fanfictions, Sherlock is overly possessive of John's time and attention, much like a person in love would be.
There's also 'The Unspoken Attraction'. This fanfic delves into the psychological aspect of their relationship. It shows how Sherlock, who is usually so detached, gradually becomes drawn to Molly's warmth and kindness. Their first kiss in this story is more of a spontaneous act that surprises both of them and sets off a new dynamic in their relationship.
One possible fanfiction could be about Sherlock and John investigating a mystery related to a 'carve baby'. Maybe it's a strange art piece or an object with a hidden meaning that they need to decipher.
The 'carve baby' in the fanfiction could be a symbol. It might represent something from Sherlock and John's past, like a case they worked on long ago that had an unresolved element related to a carved baby - like object.