Inside Boston Blue’s Challenges Over Donnie Wahlberg’s Onscreen Son’s Romance

Boston Blue just introduced a love interest for Sean — and the romance will continue to create obstacles for the youngest Reagan and dad Danny.

During the Friday, November 21, episode of the hit CBS series, Sean (Mika Amonsen) had an unconventional meet cute with Penny (Xochitl Gomez), who turned out to have a criminal record. Sean’s father, Danny (Donnie Wahlberg), specifically wasn’t thrilled with the concept of his son dating a felon.

While Danny came around by the end of the episode, the new woman in Sean’s life could cause more tension for the Reagans.

“As Danny says, ‘That crook.’ He loves that line,” Amonsen quipped during an exclusive interview with Us Weekly. “But we have our challenges. I will let viewers continue to tune in to see where it goes and if Penny returns.”

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According to a CBS press release, Gomez, 19, will guest star as Penny in multiple episodes of the Blue Bloods spinoff.

“She’ll be around and her relationship with Sean — it continues to expand,” Amonsen teased. “Danny and Sean’s relationship challenges them but I think it challenges Sean in a way as well. It feels like a first serious girlfriend for him and he learns a little bit of work and life balance.”

Boston Blue, which premiered in October, invests in Danny’s story after he was originally introduced on Blue Bloods, which ran from 2010 to 2024. The spinoff has also allowed more of a focus on Danny’s relationship with son Sean, which he is working to rebuild throughout the season.

“You’re going to see the pushback in different ways [from Danny’s side]. But you eventually see Danny recognize that his son is a full-grown man. Even when there is something that Danny disagrees with, you’re going to see him recognize that he just wants his son to be happy,” Amonsen continued. “There’s only so much Danny can impose — and Sean is at an age where he is making his own decisions.”

He added: “Regardless of Danny’s opinion, he takes a deep breath and says, ‘I just want you to be happy.’ That happens in several different ways throughout the season. We see a lot of Danny growing in opposition to Sean also growing. We see Danny really expand as a character.”

Having Danny and Sean’s reconciliation be so central to the show has allowed Amonsen and Wahlberg, 56, to put in the work on screen.

“The process has all been very, very easy. Donnie just makes it so simple. I had a pretty good understanding of the character [that was created in Blue Bloods] and I brought that and I spoke to the showrunners and writers about it,” he recalled. “[We discussed what they wanted to be] explored and where they wanted to go with the role.”

Amonsen and Wahlberg prioritized the dynamic between Danny and Sean. “Donnie was very informative — obviously — because he has so much history with the show,” he added. “Whenever I had questions, it was very, very relaxed and it felt very natural with Donnie. He has this father-like energy about him. As much as he’s been Sean’s father, he’s been a great mentor to me on how to navigate a role like this and a show like this. I couldn’t ask for a better costar.”

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The positive experience didn’t stop there. Amonsen has been able to grow Sean as a character through his work as a patrol officer alongside Marcus Scribner‘s Jonah.

“Working with Marcus is as fun as it looks on screen. He is amazing. That genuine friendship that you see between Jonah and Sean is us in real life. We hang out on our downtime and we are constantly joking around off screen. We had a really great time,” Amonsen shared. “He felt like a brother on this show. As a character, I feel like they’re more than friends because you see this brotherhood between them.”

He continued: “You will see as they navigate these difficult situations and they’re really there for each other in a way that almost feels beyond friendship. It is just what the job is — a partnership. They have a really amazing partnership where they’re always showing up for each other.”

For Amonsen, the highlight of playing Sean has been getting the “freedom to explore” who the character is now.

“My dad was a fan of the show and we’d watched it several times. But I hadn’t really gone in depth when I got the audition. I knew it was based on Blue Bloods but it all happened really quickly,” he recalled. “It was within about a week’s time and I was really thrown into it quickly. I did binge watch as much as I could and I found doing the later seasons was more helpful. I wanted to get a sense of who Sean was toward the end of the show and to really get a sense of his character at that point into adulthood and his relationship with Danny.”

Boston Blue airs on CBS Fridays at 10 p.m. ET.