Confusing sex life.

My fiance works long hours. He works from 7am to after 11pm. We see each other and talk for about an hour every night on his work nights. I ask for sex a lot and he turns me down saying he's too tiredd. Which I totally get. But then start talking about our sex life and he's like "it's been so long since you gave me any I don't even remember what it's like. " but I ask for it constantly. . He never wants it. We went away this weekend and he proposed so we had celebration sex 2 times this weekend.. when we got home I said "how about we try a 30 days of sex challenge?!?!" And he says "oh. I don't know."

Like wtf? Our sex life isn't boring. We have toys, we watch porn together, it's amazing when we actually do have sex. Why the crap doesn't he want to have sex with me though ?!?!

I have put on a good bit of weight.. is it that he's not attracted to me??

*also, I have talked to him about this. He just tells me he asks for it often and he says I turn him down ** which I have only turned him down once.. while I was sick.