imagine Greg’s confusion during the first couple of episodes. Like he knows sherlock as this druggie weirdo that like everyone hates and here comes this adorable little man with a limp whos like seemingly so useless but he compliments sherlock and finds him fascinating and Greg’s like wow okay and Sherlock just clings to John like a lost puppy and then when Sherlock comes back to Greg in his flat John’s still there and Greg’s like wow what were they coming here together for what did i interrupt he probably thought that they were on a date or something and then the glare shared between them and Greg sees the whole thing he’s probably like omg it makes so much sense sherlock is gay and then as the seasons progress he probably still thinks they’re together and then Mary comes in and Greg’s probably all like whoa wait like poor papa Lestrade probably wasn’t informed that john and sherlock weren’t together he probably just assumed throughout the whole thing 

Mycroft was willing to lose his life so that Sherlock wouldn’t have to lose another best friend. If that doesn’t make you cry then I don’t know what will.