Gf isnt putting out, she gets angry if i watch adult films ?/?

hi thanks for taking time 2 read my question, i am having some issues with my lady friend. at those times she isnt willing to participate in the act of coitus with me, i get in the car and rub one out (the car is mine), so i do watch some some adult film while im at it 2 get off, she somehow got a hunch and literally did some wise-tech stuff to my ipod and was able to monitor it ??? anyways she feels sad and she says she feels betrayed yet she wouldnt have sex with me ?? am i not entitled to sexual relief ?? she says she feels "betrayed by this" and she kinda seems sad ?? what should i do i dont even what i did wrong