In urban parlance, to creep is to cheat on one's significant other while attempting to conceal said activity. A person may be said to be "on the creep" if they look to consistently creep. To be caught creeping is an excellent way to end up a) dead, b) single, or c) married, with c) usually being caused by an ultimatum brought about by the discovery of the illicit affair by the aforementioned significant other.