Live in Boyfriend, Not enthusiastic about anymore?

My boyfriend and I have been living together for going on two years. He used to want it every day, he was always trying to get me to try new things and was really daring and ual. Always trying to get me into and just different things. Well now that he finally has me there: wanting more, trying and requesting different things, etc...now he's like over it. i have to beg him for it and like jump on him. I have to con him into having with me. I have tried talking dirty, being direct, sleeping naked, or walking around naked...i have been told im very y and very seductive and attractive...so i don't know. he's 6 years older than me...he's not old. What to do? I know he's not cheating, he works normal hours, he's eager to marry me...its just the (or lack of)