A FORMER Playboy model has revealed how she was coaxed into a steamy threesome by Spice Girl Mel B.Antonia Dorian told The Sun she was invited to a suite at the Four Seasons hotel in Beverly Hills, California, by the singer’s now-estranged husband Stephen Belafonte.She claims Mel, 42, then seduced her after cooing out from the bedroom: “Come in and say hello.”The bed covers were flung off to reveal the naked pop star, who made the first move on Antonia as Stephen watched.Antonia, 49, said last night: “Mel is absolutely gorgeous and has a fantastic body. She was definitely up for some fun and clearly really enjoyed herself.“I told her how hot she looked and she told me I had a great body as I climbed into bed with her. She made the first move and certainly didn’t have to be asked twice.”Antonia sat down with The Sun as Mel settled her domestic violence case against Stephen this week, preventing new details of drug- fuelled threesome sex tapes emerging.Mel had alleged she was often forced into threesomes by Stephen, 42. Antonia — a former adult actress who has starred in films including The Witches Of Breastwick (I & II), The…