Talk about an ironic twist: Ellen Fein, 43 — who with co-author Sherrie Schneider wrote The Rules, an infamous primer for manipulating men into marriage — is getting divorced. Worse yet, Fein's 15-year union with pharmacist Paul Feingertz, 41, is dissolving only three months before publication of The Rules III: Time-Tested Secrets for Making Your Marriage Work. Fein's publisher, AOL Time Warner, is expected to include a notation in the book's introduction mentioning the author's split.