Episode 5 of ABC's mystery drama "Mistresses" will be one of the steamiest moments of the entire season, Cartermatt says. 

According to the website, viewers will witness Dr. Karen Kim (Yunjin Kim) in a "threesome" encounter with pal Vivian (Sonja Bennett) and her husband Alec (Ed Quinn). Last episode, Vivian paid Karen a visit in a frantic state, saying Alec cancelled his appointments and never informed her about his whereabouts. The good doctor tried to pacify her and admitted that her husband was helping her recover from the marrow donation that might save Vivian's life. 

When Vivian hysterically left for home, Karen followed her. Vivian then revealed that her illness has affected her sex life with Alec. Wanting to help, the psychiatrist assisted in purchasing the sick woman sexy clothes and new makeup, which they try on over some heavy-duty marijuana. 

Alec looked surprise to see them when he eventually came home. Vivian, wanting her husband to notice her as a woman than a patient for a change, kissed Karen. Though shocked at first, Alec promptly kissed his wife's mouth. Karen was about to head for the exit, but Vivian told her to stay. Viewers then need to tune in for episode 5 to witness the next scene.

Meanwhile, April (Rochelle Aytes) is ecstatic that Blair agreed to have a date with her, while Scott (Justin Hartley) asks Joss (Jes Macallan) for his ring back. She will eventually find out that her ex-fiancée is already engaged to another woman. Her relationship with Harry (Brett Tucker) is also at the breaking point, with issues continuing to pull them apart.

Fans will also see Calista (Jennifer Esposito) dealing with more Luca complications, and she asks the ladies for help.

HWHills reports that the steamy spoiler promo clip released by ABC for the newest episode looks "very intriguing and passionate." 

"Mistresses" episode 5 titled "Threesome" airs at 8 p.m. Thursday on ABC.