I have to beg my fiance to have sex with me but yet I also catch him watching porn, why is that?

I always have to beg my fiance to have sex with me, I only want it at least once a week. And I really don't think thats asking for much. I'm 21 and hes 27 we are 6 years apart which isnt a huge age gap. but I have to beg him to do anything sexual with me, is there something wrong with me? it's not very fun when you have to beg your partner, and I have caught him watching porn numerous times. I dont care that he watches porn but how come he wants to watch porn over having sex with me? is there anything i can do? i need advice thanks!