He hates to admit it, but they've got a good groove.
Together they are unstoppable. Cato is the muscle, good with close range and hand to hand and threats. Clove is agile and nimble, with knives and torture techniques that sometimes make Cato shudder. They're friends now, though they don't acknowledge it. She's fourteen, she doesn't fit in with his friends, all strong and dumb with egos bigger than his, or tall and curvy with blonde hair and flirty smiles.
So, at lunch, he ditches them to sit with her.
(Even though she's crazy.)