Paul Turcotte didn't know his daughter's boyfriend for long, but had a few important words to tell him.
"Thank you," he told Andrew Mayzak, 23. "Thanks for saving my life."
Mayzak donated his kidney to Turcotte on Oct. 1, putting an end to Turcotte's lifetime of suffering from kidney disease.
"I made up my mind pretty quick that I wanted to do it," Mayzak told "Good Morning America." "I just wanted to make sure that her father got a second chance at life again."
When Mayzak first met his now-girlfriend, Turcotte's 20-year-old daughter, Ashley, he felt struck by her beauty. The couple said their connection came "pretty fast."
"I mean she's pretty gorgeous," Mayzak said. "I just liked everything that I read [on her dating app profile], and we started talking."
Ashley Turcotte said the feeling was mutual.
"We realized how much we really liked each other, and we just quickly fell in love," she said.
But as the couple entered their whirlwind romance, Ashley was keeping a painful family secret. Her father had been fighting -- and at times appeared to be losing -- a lifelong battle with kidney disease.
"I didn't really open up about my family or my dad at first to anyone, but I knew how much Andy meant to me, and I wanted to be honest with him and upfront," Ashley Turcotte said.
Paul Turcotte was 17 when he first started experiencing kidney problems, and in 2011, he was officially diagnosed with IGA Nephropathy, a disease where the immune system attacks the kidneys.
In 2015, the disease had grown so severe that dialysis was his only option.
"There were times when I didn't know if I could continue. I just fought through the whole thing basically," Pual Turcotte said.
For three days a week, four hours at a time, Paul Turcotte would be "tethered to a machine" -- not to mention that the father also had to balance treatment with a full-time job and taking care of his family.
"It started to get to me at times, not being able to be there for the girls and for [my wife] on birthdays and other holidays," he said.
Ashley Turcotte told "GMA" that not seeing her father as often and seeing him suffer was difficult, and she "couldn't imagine" what he was going through. So she turned to Mayzak for support and opened up to him about the struggle the family was enduring.
"He was accepting of it. He really supported me and was really great," Ashley Turcotte said.
(MORE: This woman donated her kidney to a co-worker and now they hope to send a message)For Mayzak, hearing the family's story was a call to action.
"Not only is Paul suffering, but the family is suffering … I knew I wanted to do something pretty quickly," Mayzak said.
So he got to work. Since neither Ashley Turcotte or her mother were kidney donation matches, Mayzak did some digging into whether he could be.
After about six months of tests, including blood work, urine samples, exercise, financial and even psychiatric evaluations, he got the news he wanted.
Mayzak was a match, and he knew exactly what he wanted to do.
"I didn't want to see her or her family suffer anymore," Mayzak said.
The family, which had no idea at first their daughter's boyfriend was even considering the donation, emphasized that the news was "pure excitement," though they feared for his health during the intense transplant surgery.
"I felt a sense of hope when I found out he was a match, but I also was scared for him and what could happen to him," Turcotte said.
On Oct. 1, the two men underwent successful surgeries, and now they're both doing well.
"I'm just taking it day by day. I do feel good, though," Turcotte said.
The father added that he's most looking forward to swimming again, since dialysis treatment prevented him from doing so.
Mayzak said he's in good spirits and now even tells jokes about the procedure.
"I told [Turcotte] if he ever needs a liver I'd give him one. I'm already a match!" Mayzak said, laughing.
The whole family stressed that Mayzak's generosity is something that they can never repay.
"To see [my dad] happy and healthy, it's just been really great. I can't thank him enough," Ashley said.
Ashley's mom and Turcotte's wife, Tammy, told "GMA" that she felt especially touched by the act.
"It was quite a gift, a sacrifice, a heroic thing to do, selfless … thank you just doesn't seem like a strong enough word," Tammy said.
To celebrate both men's recovery, "GMA" surprised the entire family with a free trip to Disney's Aulani Resort and Spa. This is the ultimate Hawaiian holiday -- celebrating the beauty, history and spirit of the island -- with a touch of Disney Magic.
The Walt Disney Co. is the parent company of ABC News.