Is it normal to have a "fun" buddy

so me and this guy dated in highschool for almost a year, which is a long time in highschool years. it was great and a fairytale until he broke up with me. its been almost a year since we broke up, and i know hes been with other girls and ive been with one guy but we still managed to text eachother and hook up. is that normal to do. i know im still not over him and its bad to be in this sort of relationship emotionally, but i cant help myself. everyone says the typical "you deserve better" and for me, i know i probably can, but i always end up running back to him and being genuinely happy for a couple hours, then returning back to my normal, dull self the next day contemplating on the previous night. he just came over moments ago, i gave him a bj, ive been clean for two months now, and i didnt wanna go any farther as much as i wanted to. and i know he doesnt wannt to be with me again, at least not now, cause he is enjoying his single life, and i dont blame him.