Why does my fiance keep lying about cumming inside me?

So my fiancé keeps lying to me about cumming inside me. I'm on birth control so we always do it bare and I enjoy it more knowing the momebt he's about to go. so why does he keep lying leaving me out of the good part? I get he doesnt want to disappoint me by finishing as soon as it starts but usually it doesn't bother me If he goes before I do because he can always get it back pretty quick and sometimes not even needing to stop, so we just continue and he can get off many times in a row while I enjoy it all. The thing is I enjoy the feeling and thought of knowing he's about to go especially that first time, it usually gets me off right away just thinking about it so when he denies it , it just insults me and pisses me right off that he'd lie in our most intimate moments. Its like he takes it away from both of us cuz hes trying to hold it back then lie and i dont get to enjoy it while it happens. Im on birth control so its not like hed have to lie about it to keep from wearing a condom.. he knows how upset it makes me the fact of lying more then the cumming too soon part so why does he continue to do it? He says things like "no i didn't cum check is there any cum in you? And iv actually had to show him it before he admits it. He also has said things like "i felt build up but stopped it" when later I show him the cum and then he admits how he full on felt it but lied. other times even after i show him he still lies saying no that it's just my mess not his. Or says "I was still hard so no i didnt" but he has already proven many times he can keep going after cumming.. also his precum is always clear and when he pulled out to stop, it was white like his cum. he's said things like " it's sperm in there but he didnt orgasm". Like trying to say its two seperate things orgasming and ejaculating? All while knowing we have had this argument before and knows i know better now then to believe this bs so like wtf does he still try to lie about it? all the time i either clearly see drips of it or strait up goopy pile in hand after reaching down to check or he does go limp n still tries to go at it.. if he just included me in it or not lie it be so much easier to deal with. he continues to lie so convincingly and committed that I can't trust him or know what's really going on anymore. Why does he lie so much, IIN? Especially about a thing that should be so enjoyable for both.