WordNet sense 1 (not in keeping with accepted standards of what is right or proper in polite society):

indecent, indecorous, unbecoming, unseemly, uncomely

WordNet sense 2 (not suitable or right or appropriate):

improper

WordNet sense 3 (contrary to your interests or welfare):

adverse, harmful, inauspicious

WordNet sense 4 (not encouraging or approving or pleasing):

unfavorable, unfavourable