Having finished another season of berating bad performances on ''American Idol,'' Simon Cowell is turning to another form of on-air humiliation: dating. ''The only thing more embarrassing than singing badly in public is going into a bar and making a fool of yourself in front of girls you're trying to chat up,'' says the critical Brit, who's staying behind the scenes as exec producer. ''Cupid,'' a dating show/''Idol'' hybrid, allows a lonely bachelorette (25-year-old Michigan copywriter Lisa Shannon, pictured with Cowell) to choose her own pool of suitors. Viewers then vote to select the last bachelor standing. Even if it's not a love match, Shannon may want to tough it out: She'll get a million-dollar ''dowry'' if she stays with her man for a year. ''When you're watching dating shows, you normally go, 'How can she pick somebody like that?''' Cowell says. ''This way, you can do something about it and protect her. Or you can be a complete bastard and hook her up with the wrong guy.''