Macaulay Culkin ended six years of self-imposed retirement from acting by debuting onstage in London last night. The "Home Alone" star, now 20 and separated from his wife of two years, actress Rachel Miner, plays a 15-year-old schoolboy trained in the ways of the world, specifically the sexual ways of the world, by an older French teacher in "Madame Melville." "I see this as a quality piece of art. I'm not letting my career consume me. It's just another opportunity, and I see it for what it is," the 5'8" Culkin, who reputedly earned $30 million during his movie career, told Reuters after last night's performance. Audience reaction to the play was decidedly mixed, reports the news service, which quoted a member of the first-night crowd, art gallery owner Cathy Hinde, as saying, "It was a bit contrived. Macaulay seemed awkward, embarrassed -- so young."