"Vanderpump Rules" fans should sit down in front of a fan when watching the season 12 reunion ... because Lisa Vanderpump and Andy Cohen says it's hot! We caught up with the stars as they were leaving Lisa's restaurant Sur in West Hollywood Friday night -- right after they filmed the reunion ... and they both used the word "sexy" when describing the event. Lisa told us the show was funny, joyful, tearful ... and pretty sexy -- later joking she was totally referring to herself when it comes to