Established Johnlock - John and Lestrade are out for a pint and Lestrade makes some comment about Sherlock eschewing "sentiment." John's basically like "no, he's totally sentimental! You know, just in his own way." Sherlock's way being things like "I brought you a bouquet of spleens" or something :-P Whatever it is, it's nothing anyone else would appreciate, but John totally gets the importance (maybe Sherlock remembers stupid little details nobody else would and, like, serves the exact same meal for their anniversary that they had when they first went to dinner together, right down to the pasta being slightly overcooked on the right-hand side of the plate?).

Yeah, so basically John being head over heels for Sherlock because they're a perfect match and Lestrade just rolling his eyes :-P