A longtime Fox executive who was fired last year is suing the company and Jack Zwissig, an executive coach hired to work with her, alleging that he sexually harassed her. Denise Stilwell claims Zwissig told her she “needed to lift her skirt,” among other “sexist comments.” In a 13-page lawsuit filed Friday in Los Angeles Superior Court (read it here), Stilwell alleges sexual harassment, gender discrimination and retaliation, the latter tied to her abrupt firing in…