Sherlock:
Sherlock could be the rudest person on this earth and that bothered you to no end. He could point out the most horrible thing without a second thought. You'd start argue about it which led to you screaming at each other and finally for you to storm out.
John:
John would forget things like anniversaries, birthdays and dates. He'd never notice until you or Sherlock would point it out. It often led to you crying and him upset. You'd lock yourself in the bedroom while John went out for air to calm himself.
Moriarty:
Killing people isn't something you agreed on him doing. You made him promise that he'd only take the lives of those who deserved it. But we all know he didn't keep that promise for long. You'd scream at him and he'd scream back and soon you'd start to hit him on the chest and crying your eyes out. He's quickly disappear before he'd take his anger out on you, which could lead to you death.
Greg:
He was never home anymore. He was always trying to play the hero. You argued for hours before you decided to leave. You couldn't be near him right then. You wanted him to feel how you felt when he wasn't there.
Mycroft:
Mycroft didn't acknowledged you when he was working. He said he was too busy, and you understood, but when he stopped showing up on dates and didn't go to bed you started to worry. You tried talking to him about it but he ignored you so you left for a couple of days, too clear your mind.