Ashton Kutcher and Demi Moore may not be together anymore, but that hasn't stopped Kutcher from having a relationship with his ex-stepchildren.

Last night, Moore's daughter with Bruce Willis, Rumer Willis, performed a four-song set at Hollywood's Sayers Club Sessions Presented by Jason Scoppa. Neither Bruce Willis nor Demi Moore were in attendance, but Moore's ex-husband, Ashton Kutcher, was.

Rumer seemed happy to see Ashton there, supporting her on her big night, a source told Us Weekly.

In her set, Willis performed Ann Peebles's I Can't Stand the Rain; High Low Middle by My Brightest Diamond; Otis Redding's (Sittin' On) The Dock of the Bay; and British singer Lianne La Havas's Age.

Kutcher watched attentively as Willis performed, clapping, singing along and dancing.

Ashton was swaying along and began whistling with his two fingers as she got into the song. Rumer nailed it! She sounded amazing -- very soulful, an eyewitness told Us Weekly. The crowd couldn't stop cheering and clapping as she finished. Rumer had a huge smile and blushed as she took a small bow.

As the night came to an end around 1 a.m., Kutcher and Willis shared a long hug before he left.

It seemed really happy and loving and like the two would be friendly no matter what, a source told People Magazine.