WFAN was run like a frat house, with drinking by employees starting as early as 10 a.m. and executives condoning buying prostitutes for ad clients, according to a shocking lawsuit filed Wednesday by a 40-year-old former CBS Radio ad exec. Lauren Lockwood, who worked at WFAN from 2006 until last summer, claims the station’s executives tolerated a hostile work environment that subjected her to sexual harassment. On various occasions, WFAN host Joe Benigno pressured her into having a threesome, the lawsuit, filed in Brooklyn state court, claims. Benigno “whispered in [Lockwood’s] ear about having ‘threesomes’ with him and his wife...