Susan Kelechi Watson on This Is Us' 'Definitely Alarming' Romance — and How Beth Channels Mama Carol

Everyone’s favorite This Is Us couple had more than one curveball thrown at them in the latest episode, titled “Flip a Coin.”

Beth’s mother Carol (Phylicia Rashad), whom Randall (Sterling K. Brown) described as “Supreme Court-level judgey,” returned, this time for the grand opening of her daughter’s new dance studio. But it didn’t go as planned as the family found a carcass in the building’s vent 30 minutes before guests arrived.

As Beth and Mama C targeted the cause of the horrid smell (a dead possum), Randall met Malik (Asante Blackk) for the first time, quickly learning that the high school junior, who is two grades older than their freshman daughter Deja (Lyric Ross), is a father to a 6-month-old baby girl.

And Susan Kelechi Watson tells PEOPLE that Deja and Malik’s romance is “definitely alarming” to Beth and Randall as more episodes will show.

“Beth is still learning how to treat Deja, it’s only been with them for two years. She wants Deja to feel comfortable and acclimated in the family but also wants to treat her like her birth daughter. And protect her in the same way,” Watson says. “There’s a bit of a trying to step a little lighter than she would normally. But she also wants to show that she cares and does matter. The pace that she moves with boys and all those things, it’s a work in progress. It’s definitely alarming to her and Randall.”

And typical with the time-jumping series, fans traveled to the past and learned more about Randall and Beth’s college love story — that served as a “cool juxtaposition” to Malik and Deja’s budding relationship.

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“I know that the past a lot of times and stories will reflect some of what’s happening in the present. I feel like it’s always been a curiosity of how Beth and Randall met and what their relationship was like beforehand. It is a cool juxtaposition of Beth and Randall in the past with Deja and Malik in the future,” Watson explains.

On the blossoming romances of past and present, the actress shares: “To see how Randall and Beth got through things when they first met or how she learned things about Randall when they first met, and how she knows about those things now as an adult and how she deals with that. All of those elements work by seeing them in the past.”

As Malik and Deja get more serious, Watson foreshadows Beth channeling a little bit of Mama C “in a different way, but with some of that same quality.”

“I don’t think Beth is as necessarily strict as Carol. But that quality of being super protective is there for her girls. I definitely feel that Beth wants to be sure that no matter what happens Deja is okay and that she ends up in relationships that are good for her,” Watson says. “Beth also wants to be sure that Deja stays open with her and Randall. And that she feels free to tell them things, that’s the most important thing that she stays open and honest with them and that they know what goes on — because kids can always hide stuff. We don’t know anything.”

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Speaking of Mama C, Watson says her on-screen mom brings extra pressure for Beth to succeed with a new business in a new town.

“For Beth, we know the relationship so there’s always pressure to perform when Mama C is around. She feels like her mom is always thinking that dance studio was never a good idea and Beth’s now proving that it wasn’t a good idea,” she explains. “It’s always a lot of pressure for Beth to do well with this because it’s obviously the thing her mother was most afraid for Beth to pursue. She wants her to be successful so it’s just the beginnings of that tension and finally making her mom proud.”

In the season 3 finale, a flashforward showed what appeared to be a prestigious dance company led by Beth, which begs the question: Will Watson be putting on her dancing shoes again?

“They say so, I love doing it. Dance is Beth’s career now, so I imagine there will be moments in the dance studio and more moments for Beth to hit the dance floor and really shows how much she loves it and invest in it,” Watson hints.

This Is Us airs Tuesdays (9 p.m. ET) on NBC.