Are they playing me or is it the other way around ?

so i am gay ,but the chicks in my class don't know that , and every-time we go clubbing or smth their like dirty dancing with me like grinding and stuff , i mean i don't mind but its awkward and am sure its not cz they have a crush on me cz they all do it , and only with me they dance very clean wid other guys in my class ....and they can't possibly know am gay since am str8t acting and am careful of gossipers ! is this weird ?