How to reject him in a way that makes him think twice

So for context I went out wtih this guy who is amazing and hot. Pretty much he has no apparant red flags and he was extremely respectull and woke as hell. Here in lies th problem though, he isnt looking for anything sefious right now. I am though, I thought U was okay sith something casual but when I thought it over I decided that no I wasnt. I know what I want and its to have partner. I also know myself and know id end up catching feelings. I really like him though and this is not like some weird desperate thing tomake him fall in love with me . I just think that if he pulled his head out his ass he would realize that im not just a hookup. That being said I want to know a good way to tuen him down for sex that would either make him feel like "damn I am going to miss out" Or even just " damn this btch is even hotter now and I dont even get the sex" I want him eifhee way to think twice after I turn him down. I also would like suggestions for fhe future as well. Im geeat at turning down asshiles but guys who are kind and respectful are not in my repetoire.