teen relationships 😣

we're long distance but we do have sex. (when we see eachother obviously) today out of the blue he said "i highly doubt you want to have sex" i'm like WHAT???? and he's been acting weird ever since like he said "i just don't think you're attracted to me anymore"   ????!!!!!!! WHAT WHAT i'm so confused on why someone would say that. we've been dating for 1 year and 11 months today and i know it's silly but we always wish a happy anniversary every 29th of the month and i didn't today and he said it earliee this evening and said "i've been waiting for you to say that all day." 

any ideas why someone would act this way? i asked him but he just said "idk i just feel like that."