An unlikely duo. 

Allison Janney and Andrew Rannells co-star in the HBO movie, “Miss You, Love You,” which follows Diane (Janney) a grieving widow who is planning her husband’s funeral with help from a stranger — her son’s assistant, Jamie (Rannells). 

The Oscar-winning actress exclusively told the Post that she had “fun” filming it, because she likes material that is “the messier, the better. For me, comic mixed with drama and anger … comedy [mixed with] intense hurt, that’s when it’s really spicy.” 

Written and directed by “Community” actor Jim Rash, the movie oscillates between comedy and drama. Diane is rude to Jamie, and they both acknowledge how strange their situation is.

She’s estranged from her hotshot author son, who is also stuck overseas. So his assistant Jamie goes to stay with Diane in his place, helping her in her time of grief. Eventually, Diane and Jamie bond.

Rash exclusively told The Post that he was inspired by his experience at his own father’s funeral eight years ago. 

“My sister had her assistant with her, because she was dealing with some work stuff, and I had never met her assistant — no one had. He didn’t know anyone in the room. So, I just thought that was very fascinating to watch someone in a very emotionally vulnerable place with strangers.”

The “I, Tonya” actress said she leaned into “feelings of anger and resentment,” to play Diane, and the “frustrating feelings of a relationship that’s not what you want it to be.”

Janney said she could relate to Diane’s desire to, “find connection, be understood,” and “be seen.”

She quipped, “I’m not as caustic and spicy as Diane is” or as much of a “control freak” like the character, but it was, “fun to to jump into that skin, a little bit.” 

The movie is was filmed in 17 days, they said. 

“We had so much time together in this very small little holding room,” Rannells exclusively told the Post.

The “Girls” actor noted, “It could have gone awry, but it never did, because we both knew when to not talk and when we needed space.” 

When they did talk, he said, “I would try to get [Janney] to do lines from ‘Drop Dead Gorgeous.” 

The actress was “a good sport about it,” he said. 

“And I had a lot of ‘I, Tonya’ questions.” He also talked to Janney about her past work on “The West Wing,” and she had “patience” with him, Rannells said.  

The two actors had previously met when Rannells was starring in Broadway’s “The Book of Mormon.”

“I’m so glad that I knew him before, because otherwise I’m like, ‘who is this?’” Janney told The Post. 

She added that she “immediately” knew “I was going to have fun with him,” because they both have theater backgrounds. 

“We knew what the mission was, and we were going to kill it.”

“Miss You, Love You” premiers Friday (May 29) at 8 p.m. on HBO and streams on HBO Max.