“We got the fairytale. We know the ending, so far.”

Conjoined Twins Lexi and Sydney 1
Credit: The Starks/NBC News

Twins Sydney and Lexi Stark were already lucky when they were born on March 9, 2001. Though they were conjoined in their lower body, they had defied the odds — 40 to 60 percent of conjoined twins are delivered stillborn, and only 35 percent survive after the first day. But seven months later, the girls were successfully separated during a risky surgery, and now, at age 17, they’re thriving.

“I think it was always, they will survive,” the girls’ father, James, said of the family’s mindset going into their birth during Monday’s episode of Megyn Kelly Today. “I don’t think it was ever a question.”

He and his wife, Emily, learned during a doctor’s visit prior to the twins’ birth that they were conjoined.

“I just remember looking at the ceiling, and I just kind of tuned out,” she said. “And James kind of took over from there.”

“Obviously we knew what conjoined twins were, you see stories and you read about them,” James said. “[The doctor] brought out this thousand-page medical book and flipped through it to the page on conjoined twins and there was literally two paragraphs on conjoined twins.”

But the family stayed positive, and James was cracking jokes the day Lexi and Sydney were born.

“The girls were squirming and James went over to Lexi and he said, ‘Oh Lexi, are you having a nightmare that your sister is stuck to your butt?’ And all the nurses giggled. They were like, okay, this family is going to be just fine,” Emily recalled.

Conjoined Twins Lexi and Sydney 2
Credit: The Starks/NBC News

On Oct. 9, they brought the girls into the hospital for their separation surgery. Because they were joined at the spine and shared a spinal cord along with some intestines, the doctor said there was a serious risk that one or both would be paralyzed, or die.

“We had done so many things to get to this day, and about two weeks before I looked at James and I said, are we playing God? Are we messing with perfection? Because we could keep them together and we could keep them, but are we messing this up?” Emily said. But James said they had spent months — both before the twins’ birth and in the time leading up to the surgery — coming to their choice.

“At the end of the day you have to trust that you made the right decision with the information you had at the time,” he said. “If something went wrong, you’re never prepared for that, but at least you went into it knowing what you were doing.”

And after hours in surgery, Lexi and Sydney were successfully separated.

“The room just exploded, you could hear that ‘Woohoo! Two babies!’ ” Emily recalled. “We got the fairytale. We know the ending, so far.”

Now the girls are entering their senior year of high school, and share a few twin quirks — they can tell when one is upset or in pain, even when they’re completely apart.

Conjoined Twins Lexi and Sydney 3
Credit: Nathan Congleton/NBC

“In upsetting situations, sometimes I won’t get upset, I’ll be like, that’s not a big deal. While she’s over here like, that’s so awful, oh my goodness and freaking out for me,” Lexi said.

“Sometimes I won’t know and she’ll come home and say I had a bad day, and I’ll be like, ‘Oh there it is,’ ” Sydney explained.

And they may be even further apart in just a year — Sydney hopes to go to college at the University of Missouri in St. Louis, while Lexi is aiming for the University of Calgary.

“So not only is it a different state, it’s a different country,” Sydney said.