A Manhattan literary agent is suing the best-selling author of the mean-girls bible “Why Men Love Bitches,” claiming the writer stiffed him out of royalties.

Agent Harvey Klinger says Sherry Argov refuses to pay him, despite signing an agreement that “irrevocably appoints” him as her rep, according to a Manhattan Supreme Court suit.

Argov’s lawyer says his client cut ties with Klinger 14 years ago.