This angel was pretty unholy. “Charlie’s Angels” star Jaclyn Smith revealed her castmate Tanya Roberts once propositioned her for a threesome with her and her husband. Speaking about her time on “Charlie’s Angels” in her newly released “I Once Knew a Guy Named Charlie” memoir, Smith recalled Tanya’s open marriage with her husband, Barry Roberts. Tanya “wasn’t shy about it in the least, or about propositioning people to ‘swing’ with them,” Smith wrote before diving into her own experience. The “Bourne Identity” star recalled that, during a flight to Hawaii, Tanya asked her to join her and Barry for a threesome. Despite declining, she…