Barry Allen/The Flash:
How you were always there for him, especially when his mother died and his father was framed.
How you always went with him to visit his dad in jail.
How you were the first and oldest friend in his life.
How you were the first one in his normal life he told was the Flash.
How you were there for him whenever he went to his brother's birthday parties that made him feel awkward.
How you always went him to his family.
How you accepted him completely when he got his powers.
How you always watch the entire Star Trek movies with him every movie nights.
How you always accept him.
How you always accept his corny jokes and puns.
Leonard Snart/Captain Cold:
How good you are in using his Cold Gun.
How smart you can be during heists.
How you're always there for him as backup, and when things go south.
How you're always there in the darkest times.
How you never give up on him.
How you're one of his best planners for his heists.
How your suggestions can sometimes save him and Mick's life.
How you and Mick are like annoying Brother and sister.
How good you and Lisa get along.
How good you are a listener when he talks about his past.
How he trusts you completely.
How you can often be almost as sarcastic as him.
How you can be such a badass.