Sorry but I just don't get this.
Maybe we do things differently on the planet I come from, a place called "Earth". There, it is quite permissible to talk to strangers but convention says that touching, usually in a "neutral" non-threatening area like a shoulder, is generally reserved for people we know or at least feel comfortable with. Touching breasts, buttocks or a man's privates is reserved for very close friends or sexual partners and then only in private. In the early stages of a relationship of course a man will want to touch but, unless he is an ignorant yob, he will approach this slowly and gently and either seek permission first or give you ample time to object.
If someone "casually" touches your breasts in public on a first or early meeting he is overstepping the bounds of polite behaviour by a wide margin and, at the very least, that should be the end of any chatting. The guy obviously has no manners and no respect for women and is not someone you want to know.
