CBS will debut an all-new episode of "Two and a Half Men" on Thursday, featuring Walden's new love interest.

In a video promo of the upcoming episode, "How To Get Rid of Alan Harper," Alan is enamored with his new girlfriend Gretchen who is an attractive woman with similar interests and characteristics. She will be played by actress Kimberly Williams-Paisley.

According to BroadwayWorld, the synopsis states that: "Walden suspects his new girlfriend is cheating on him. Meanwhile, Alan gets even more intertwined in Lyndsey and Larry's relationship when he starts dating Larry's sister, Gretchen."

On Tuesday, CBS announced that Mila Kunis will appear opposite her real-life boyfriend Ashton Kutcher as a guest-star in an upcoming episode of "Two and a Half Men," reports The Hollywood Reporter. This will mark the couple's first appearance together on television since they starred in "That '70s Show." The two met back in 1998 on set at the Fox sitcom and have been dating for the last two years.

Kunis will play Vivian, a young, beautiful and free-spirited world traveler who shows up on Walden's doorstep. In turn, Walden, who was about to propose to someone else, will feel an instant connection with her and become convinced that she's the one.

Kunis, a voice actor on Fox's "Family Guy," has starred in a number of movies including "Black Swan," "Oz the Great and Powerful," "Ted," "Friends With Benefits" and "Forgetting Sarah Marshall." She will next be seen in "Jupiter Ascending" and "Third Person."

"Two and a Half Men" S11E16, "How To Get Rid of Alan Harper," airs on Thursday, March 6 at 9 p.m. EST on CBS.

Watch a preview of the show below.