Step by Step’s Christopher Castile, Who Quit Acting After the Show, Reflects on Dramatic Transition from Child Star to High School Teacher

Former child star turned high school teacher Christopher Castile brought his experience as an educator to revisit an episode of Step by Step this week.

Castile, who played nerdy middle sibling Mark on the ’90s sitcom, joined his TV sisters Staci Keanan and Christine Lakin on the most recent episode of their rewatch podcast Keanan and Lakin Give You Déjà Vu.

The trio kicked off their conversation by diving into Castile’s transition from child actor to a teacher of high school economics and history. He explained that after Step by Step ended in 1998, he finished high school and went on to college.

“I had no idea what I wanted to major in, but I really liked music, and I thought I wanted to be an orchestra conductor,” he recalled.

Ultimately, however, he got a degree in political science with a minor in economics. After a stint in grad school, Castile said he thought he would go on to become an academic. But the 2008 recession stymied that plan.

“I just picked up a bunch of odd jobs,” he said. “I was a tennis instructor. I was a custodian for a while to help put me through graduate school. And then someone who I knew at church was like, ‘Hey, why don’t you be a high school teacher?’ ”

After initially resisting the idea, Castile said he remembered enjoying adjunct teaching while getting his graduate degree.

“So, I got my teaching credential. And after I did my student teaching — which is kinda like an unpaid internship where you see if you like it, and then that’s where you get your license from the state — I was like, ‘Okay, so now I need to start applying for jobs.’ And fortunately, the high school where I did my student teaching had a job opening. And I’ve been working there since 2012. And I love it,” he explained.

While Castile, who also starred in 1992’s Beethoven, hasn’t acted since 1998, he noted that he still performs — in a way.

“I’m a high school teacher, so it’s really performing,” he explained. “You’re trying to, like, sell the students on the content, sell the students on yourself. So, yeah, I do perform. It’s just not SAG work.”

Castile’s teaching experience definitely came in handy during the trio’s recap of the second episode of Step by Step’s second season, “To B or Not to Be,” which found older sibling J.T. (Brandon Call) struggling in his high school English class.

Keanan, Lakin and Castile noted that a plot point about Call’s character frequently falling asleep in class wasn’t far off from real life.

“Brandon was not a huge fan of school,” Castile recalled. “There was a beanbag chair in the school room, and he spent a good bit of time in said beanbag chair trying to figure out a way for Susie, our school teacher, to not realize that he was sleeping.”

Castile also shared a “trick of the trade” for dealing with students who fall asleep in class.

“I’ve known a few teachers to do this,” he said. “I myself have done it three or four times. The thing that you do is you turn the lights out and you have all of the students exit the room. And you either, like, make some type of, like, loud noise and they’re in a dark room. Like, for many years, I had a room with no windows, so we called it ‘the cave.’ It was pitch black in there. So, this usually leads to a student, you know, being jolted awake and freaked out that they are in a dark room, which is kinda fun.”

The episode also saw Carol (Suzanne Somers) initially siding with J.T.’s teacher over his difficulties in class, but later standing up for her stepson when she realizes that the teacher has graded his work unfairly. Noting that she frequently sees teachers on TikTok posting about their experiences with difficult parents, Keanan wondered whether the dynamic has shifted since the ’90s, with parents now more likely to assume that teachers are the problem.

“I see both,” Castile said. “There are times when the parent will assume that their kid is giving their all and it’s a me problem. That tends to not happen as often. I still feel like there’s a good bit of parents that will approach it like Carol first did, which is: What can we do, or what can my student, do?”

“I’m fortunate that I work in a public school, and we have a union, and we also have a very, very, like, supportive team of administrators,” he added. “Usually, it’s pretty easy to work out. And there are some teachers that might be more difficult than others. My motto in life is: How can I just make this problem go away? That’s my motto in life. So, if I happen to get a parent that will more likely side with the kid, then we just find a creative solution and try to make people as happy as they possibly can be while still, you know, keeping the rigor for the class.”