The Attention.

Makima decided to be extra bitchy towards your girlfriend and make her jealous with her looks. That's it, she's just rage bating for the love of the game.

(I would change the pfp, i just wanted some excuse to use this one.)

(Having an affair with Makima is optional, Makima is just showing that she can attract attention with ease but to her it would be a plus that you start cheating on your gf with her.)