How do i deal with a man who keep chasing me despite my clear warning of lack of attraction for him as he is not my type and not attractive to me.

I find him extremely unattractive but he is not taking "no" for answer and keep chasing me and also when i started dating other guys he got jealous and started disturbing my dating life , maybe tomorrow even my marriage life !

I told him many times , even spit on his face saying he is ugly but he still chasing me! He was acting delusional about my rejection and kept chasing me.

I used to admire him at first ( which he might took it as attraction which is weird though, why would anyone confuse something like that as attraction).