Miley Cyrus guy pal' Justin Gaston has been given the seal of approval by her protective father Billy Ray.The 15-year-old has been linked to 20-year-old Gaston - a former contestant on reality TV show Nashville Star - for several weeks, and he joined her dad onstage to perform at Miley's Disneyland party on Sunday.All parties have denied Gaston is romancing the underage star - but he has won over Billy Ray.He tells Access Hollywood, "He actually reminds me a lot of myself when I was 20-years-old and I was living and searching for the dream. He's got a great heart and soul, and a lot of determination. I think that's the true measure of a man, is when you measure his heart."