Source: My PaperKelly Clarkson, who was the first contestant to win American Idol a decade ago and went on to several chart-topping successes, has got engaged to her boyfriend, the singer said in a Twitter message last Saturday.Clarkson, 30, earlier revealed she had been dating talent manager Brandon Blackstock since early this year.Blackstock is the stepson of country singer Reba McEntire."I'm engaged!"Clarkson said on Twitter."I wanted y'all to know!! Happiest night of my life last night!"She then followed that by posting a link to a photo of her canary- yellow diamond engagement ring on a website.She wrote that her fiance helped design it and that she "can't wait to make Brandon's ring".Last month, in an appearance on the Ellen DeGeneres Show, Clarkson said she had been dating Blackstock since this year and was thankful to have him."I am not alone for the first time for Thanksgiving and Christmas and I'm very happy," she said candidly on the show.She said then that she expected that they would get engaged, but that they would "totally, probably elope".