What should i do?

Me and my friend were having a talk about her ex whom cheated on her so me and her were at lunch talking at lunch and i rolled my eyes but i was playing but when she talk about her ex she act like she hate him but she think i don't know that she really love him still i respect but why lie about how u feel, but whenever i talked to her about my problems she would make a lil joke and i wouldn't get mad but i should have but i didn't but right now she's mad and i stay with her and we go to the same school i been through a lot in my life i really have honestly