Mila Kunis, Ashton Kutcher "Open with Their Affection" During Lunch Date

Seems like things are continuing to heat up between longtime friends Ashton Kutcher and Mila Kunis.

While grabbing lunch at L.A.'s exclusive Soho House on Saturday, the "That 70s' Show" costars shared an intimate meal together while packing on the PDA.

"They were seated on a couch on the same side of the table and Mila was running her hands through Ashton's hair," a witness tells Us Weekly. "She had her elbow resting on his back and couldn't stop playing with his hair and rubbing his shoulders. He leaned in and whispered to her and kissed her cheek. They were holding hands."

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The pair have been hanging out since late April doing everything from road trips to dining out in public. A source recently told Us, "They're not exclusive, but they are hanging out and seeing where it's going."

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Keeping their relationship undefined may be just what the doctor ordered for Kutcher, 34, who split from wife Demi Moore after six years in November 2011, and Kunis, 28, who tells July's Glamour magazine, "I've never dated. I can say this honestly: I don't know what it's like to date."

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But in the meantime, their private, one-on-one interactions look like two friends who are making up for lost time.

"They seemed to feel safe and were being open with their affection," the witness from Soho House tells Us.

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