Mila Kunis and Ashton Kutcher during a walk in the West Village, NYC on September 23, 2012. Credit:

Could Mila Kunis soon be sporting a little red bracelet?

The actress accompanied beau of six months Ashton Kutcher to Rosh Hashanah holiday services at the Kabbalah Center in NYC September 18.

"The men and women are separated [during the service], but Ashton always smiled at her," an eyewitness tells Us Weekly.

Afterward, Kutcher "ran to embrace her," the witness adds. "They were clapping and praying. She was taking it all in."

The Two and a Half Men actor, 34, first joined the sect popular with celebrities like Madonna in 2003, with his now-estranged wife Demi Moore. (Last fall, as Moore and Kutcher struggled to save their marriage, they turned to a counseling center with Kabbalah affiliations.)

Now, Kutcher is determined to make it work with -- and open up his life to -- his former That '70s Show costar, 29.

"He always had a thing for [Mila]," a source recently told Us. "It's a real infatuation."