By Serena Kappes
June 22, 2004 08:00 PM

No, it’s not a Punk’d stunt: Demi Moore, 41, and Ashton Kutcher, 26, are expecting a baby together, PEOPLE has learned. Sources tell the magazine that Moore is due TK. (MORE DETAILS TK.) This will be his first and her fourth child (joining daughters Rumer, 15; Scout, 12; and Tallulah, 10, with Bruce Willis).

Rumors had been swirling recently that the May-December couple were planning to marry – though in January, during an appearance on Late Night with David Letterman, Kutcher had said a wedding was “not in the datebook.”

The couple have kept a high profile since they first went public with their romance in May 2003: They’ve attended family outings with Moore’s ex-husband Willis (including his 49th birthday party in March at L.A.’s Spider Club), hit the movie premiere-and-party circuit and become devotees of Kabbalah, the study of Jewish mysticism.

Kutcher has also been seen regularly with Moore’s children. “I try to help them with the problems they have, and they bring me a lot of joy,” the That ’70s Show star has told PEOPLE. “But to really define what I am to them would be very difficult.”

Moore is due to start shooting the supernatural thriller Half Light in the U.K., Ireland and Wales in August.