Stunning big-screen starlet Uma Thurman is engaged to her multimillionaire boyfriend, Arpad 'Arki' Busson, according to People.com. The couple met last summer at a private dinner party in Milan and have been dating across continents ever since. Busson is said to have proposed to Thurman with an 8-plus carat diamond ring. "It's the most beautiful piece I've ever seen," says a close source. The couple, who has four children between them, has yet to reveal any wedding plans.