Katniss and Finnick

(Spoilers for the Hunger Games Trilogy)
So, you guys know me well enough that you should know that I don't ship this. At all. I am a hardcore Toast shipper. (Katniss and Peeta, bros.) But this is the cutest friendship ever. Almost as cute as the Golden Trio. Almost, that is.
When Katniss meets Finnick, she knows she can't trust this guy. This flirtatious kid isn't worth her time. And it stayed that way for a while. But what Haymitch says, in general, goes, so when he decided that Katniss and Finnick were to be allies, they were to be allies. I'm not totally sure Katniss trusted Finnick at all in Catching Fire. I think she started liking him enough. But you don't want to make a connection like that with someone you know you will have to kill if you want to keep someone else alive, and it didn't help that after she got out of the arena she found out that he was in on the plan to get her out of the arena alive, even if it meant sacrificing Peeta. Honestly, Finnick started to become Katniss's friend in the first place because of the rebellion. If Katniss wasn't going to help the rebellion, then they might have not even formally met.
In Mockingjay, that's when they really started becoming friends. Maybe it was that they could relate to each other. Peeta and Annie were both being tortured in the Capitol. It helped to be able to talk to someone who understood what they were feeling, and it actually helps you forget about your troubles to do something for someone else, so caring about what they other felt and what happened to the other and taking care of the other, that's what helped them get through it. You know it's true friendship when he shares his rope with her! That's so cute!