misbehaving

defiant, disrespectful, ill-mannered, ill-natured, impolite, improper, impudent, indecorous, insolent, rude, uncouth, unmannerly

disobedient, headstrong, intractable, obstreperous, recalcitrant, refractory, transgressing, unruly, untoward, willful (or wilful)

balky, restive, uncontrollable, ungovernable, wayward, wild

arch, elfish, impish, knavish, monkeying, monkeyish, ornery, pixieish, prankish, rascally, roguish, waggish

dissolute, perverse, wrongheaded

disorderly, rowdy, ruffianly

corrupt, evil, wicked

insurgent, mutinous, rebellious

disobliging, inconsiderate, selfish, thoughtless, unkind, unkindly

babyish, childish, immature, infantile, jejune, juvenile, kiddish, puerile