The children are suddenly introduced to yet another authority figure. Someone they might not even know that well.
Someone who might, in some ways, remind them of their biological parent, now absent from their household.
Or, in fact, someone completely anathema to their previous life. This, on top of possibly having to move homes and change schools.
It's no easy task. Everyone is caught in the waves of change.
One step-dad turned to Reddit to express his frustration.
"There was one time that I literally could not get the two youngest off of the trampoline soon after my wife and I got married," he begins.
The family—including the two children jumping on the trampoline—had an event that they had to get to, which step-dad Reddit user 'inflammable' had made clear from the get-go.
"I gave them several reminders and warnings up until sure enough, the time came and went. I tried incentives, I tried threats, I screamed at the top of my lungs, the 11-year-old literally laughed at me and said, 'Whatever inflammable [stepdad's Reddit username], we don't have to listen to you.'"
Hearing this, parents of the internet gathered to help solve this stepdad's problem. Here's what they suggest.
1. Get your partner on your side
"Kids testing boundaries is very normal," says one user on Reddit.
"Stepdads—especially childless stepdads—getting hung up on disrespect is also very normal."
"The first rule of parenting (step or otherwise) is that the two of you need to be a united front. Start there. Set up a system where each of you backs the other up. Find out what you agree on and what you disagree on."
A user named nikkorizz chimes in agreement:
"To the kids, you're a new guy coming into their territory and setting up new rules…'doing things differently than mom.' Add the fact that they are all teenagers, so they are going to naturally rebel."
"Cultivate your friendship with them first," the user says.
"Love them and root for them when needed. If trouble happens at school, side with your kids first."
When it comes to house rules, one parent encourages new step parents to act as enforcers instead of lawmakers. This leaves the children's biological parent to write the law of the land: making sure the kids know you, the step parent, aren't making up harsh punishments as you go along.
Reasons one parent:
"They are more likely to listen to you if they know the rules came from [the parent they grew up with]."
2. Remove a privilege if they don't listen
While stressing the importance of explaining your reasoning—crucial as it is to a child learning right from wrong—it won't always work.
And it can get really frustrating.
Before going berserk on the young ones, who, let's be real, have only recently become your children, remind yourself of a more helpful approach.
"Make the trampoline not usable," says one.
"With the video game systems, take the controllers," adds the same parent. "They need to learn boundaries."
Another parent discourages step moms and dads from "getting into back-and-forth arguments" with riled-up children.
"That is you…giving the impression that the statements you make are all negotiable. This does not engender respectful behavior. If the kids won't get off the trampoline to attend a time-sensitive event when [your partner's] not home, well, they'll have to miss the event. Oh, and inflammable (another Reddit user) has changed [their] wi-fi password."
3. Whatever you do, don't get physical
Again. They have only recently become your children.
They might not even be ready to call you their parent yet, in which case, physically aggressive behavior is 100 percent off-limits.
One parent, a stepdad of 13 years, explains:
"If weekend dad [or mom] are around, they could cause problems. If they aren't, I still wouldn't recommend getting physical as in some cases, it won't help anyway and [it will probably] exasperate them further."
Another parent is quick to add the obvious.
"You don't want to set up a dynamic of them just waiting for the day they think they can take you," TelescopeFeed says.
4. Pick your battles
"Infractions like underpants on the ground are small fry," urges one parent.
"If the kids will really burn the house down without your supervision, ignore the small stuff and focus on the big stuff, otherwise you will come off as a nagger. [Your partner] can deal with the underpants."
A veteran stepdad puts it simply.
"Know when to let s**t slide and when it won't be the end of the world," he says.
"You're not going to win every fight," agrees another. "But that's okay. You are in an impossible position."
And most importantly:
5. Show them your love consistently.
TelescopeFeed says it best:
"Love them unabashedly. They're watching for it. If you fail to, they'll point to it as evidence that you're not worthy of the role you've assumed. Their only frame of reference is [your partner's ex]. If he or she ignores their protests for hugs and hugs them anyway, that is a measure they will use for how a parent expresses their love. If he or she smiles broadly when they sees [the kids] and embraces them enthusiastically, you have to do that too (whether they reciprocate or not), because that is how they measure whether you love them like [your own]."
"A [parent] doesn't give [kids] their space," they add. "Keep that in mind."