Ryan Reynolds and Blake Lively’s son, Olin, did them a simple favor by coming last.

The actor joked on “Late Night With Seth Meyers” Thursday that he “would never” have had four children if his baby boy was born first.

The Golden Globe nominee confirmed that welcoming the little one in 2023 after daughters James, 10, Inez, 9, and Betty, 6, was a “jarring” experience.

Reynolds explained that there was “nothing violent” or “creepy” going on in their New York home before Olin’s arrival.

“He came out with three things on his mind,” the Emmy winner quipped. “It was violence, breasts and engines.”

The “Deadpool” star noted that his girls were “just so easy” compared to a son who wants to “break everything.”

He would have given himself a “punching vasectomy” before having “three boys at first” — something he would not have “allow[ed] to happen.”

When Seth Meyers asked whether James, Inez and Betty feel like Olin is “an HR issue,” Reynolds replied, “I do.”

He joked, “I’m, like, in direct competition with this young man.”

Lively, 38, referred to Olin as “romantic” in a March sitdown with Meyers.

“When I walk in, he goes, ‘Mama, my love!’” the actress gushed at the time. “He just, like, announces that I’m the love of his life at all times, which is just the best feeling in the world.

“I get dressed every day like I’m a girl in middle school,” the “Gossip Girl” alum continued. “Like, ‘Oh, my gosh … I hope he, like, says something.’”

She called their house “chaos” and compared one of her daughters, whom she did not name, to birthday twins Napoleon Bonaparte and Jennifer Lawrence.

“She’s the funniest person in the world, but she will definitely rule the world with authoritarian leadership,” Lively said, seemingly referencing Betty.

Lively, who has chosen to keep her kids out of the spotlight, also addressed her legal drama with “It Ends With Us” co-star Justin Baldoni in the interview.

She noted that during her “pretty intense year,” James, Inez, Betty and Olin have been her “lifeline … no matter what day” she is having.

Lively accused Baldoni of sexual harassment in December 2024 — and the 41-year-old countersued her the following month, only for the lawsuit to be tossed out by a judge in June.

As Lively’s lawsuit drags on, the actor recently hired Sean “Diddy” Combs’ lawyer Alexandra Shapiro to join his stacked legal team.