What should i do?

So basically theres a weird guy that kept touching my back and waist even thought i told many times that i don't like being touched, he is really a weird guy (He does very disgusting stuff that i don't like to mention)

But i feel like if i point him out he will get some ppl and try to hurt me or smth (he is like the kind of guys that are nothing without a gang and that stuff but i don't really have those kind of groups or ppl that could try to support me if something happens) Also there was a time where he kissed the back of my head (i don't even like him and that was very disgusting)