sometimes he has to watch porn after sex...

My boyfriend and i have sex at least once a day and sometimes he can not stay hard long enough to finish and will then go to the bathroom and watch porn to finish his no longer hard masturbation session.. I would understand if maybe he did it on his own time or say if i was away, on my period, or just not giving him any but im right here... He seriously always wants to have sex and gets turned on by me and always tells me how sexy i am.. i mean ALWAYS... i can't change clothes without him wanting to have sex... But right after sex with me for an hour or so he goes to the bathroom to watch porn and can get off i feel as though im not good enough and it irritates me that he is watching other women have sex and imagining them to get off...i always say,  "I AM RIGHT HERE, WANT PORN? ILL DANCE FOR YOU, MASTURBATE FOR YOU, DO WHATEVER YOU NEED ME TO, TO GET YOU OFF" But he never asks me to do any of that for him or anything... I honestly see it as a form of cheating because he is looking at another woman while imagining them when he could be making love with his woman... but he does it often after sex and i feel incompetent at pleasing him.. =(

Sorry the post is all over the place but i am furious right now and emotional... there was a lot in my head that needed to get out. please help me figure out what im doing wrong. or what he should or shouldn't be doing...