why do you think that it is an inappropriate advance? what is a proper one? I have no info to sustain it being inappropriate other than the OP saying that he was upset by it.
And he could be upset by a number of reasons.<p>Inappropriate would be groping, or very obscene talk, and especially those or continue hitting on someone after she said stop.
MILF is borderline.<p>OP might be upset for other reasons as well.. OP, just consider that.