You two were best Friends. After he mentored you, you were pretty much inseparable. You were sorta close in age when you went into the games so it made sense.

When you were reaped for the games a second time you made a pact to never split up in that arena. And never split up you did.

You stayed together the whole time. You allied with Katniss and Peeta so you were more than safe (for now). So now you're all just sitting on the beach.

Finnick's trying to get food, Peeta is helping by opening oysters with his machete, and you and Katniss are sitting on the sand looking out at the waves that should not be as beautiful as they are.