The Collaborative International Dictionary of English v.0.48:
overfamiliar \overfamiliar\ adj. Taking undue liberties; assuming an unwarranted tone of familiarity. Syn: familiar. [WordNet 1.5 +PJC]WordNet (r) 3.0 (2006):
overfamiliar adj 1: taking undue liberties; "young women disliked the overfamiliar tone he took with them"