(CNN) -- Dressed in a tan suit and an orange shirt matching his mom's bouquet, 2-year-old Logan looked on as his parents exchanged vows and rings at a backyard wedding.
Guests who gathered under a white arbor in the Jeanette, Pennsylvania, home applauded -- but many with tears in their eyes.
Because this union of Christine Swidorsky and Sean Stevenson was no ordinary wedding.
The couple had planned it for ages, and had penciled July 2014 as their special day. But that was before they learned that their best man -- Logan -- had just weeks to live.
The boy is suffering from leukemia, brought on by a genetic disorder, Fanconi anemia.
"We've been waiting for this day for a long time, but under the circumstances with Logan being sick all the time, we just held off," Stevenson told CNN affiliate KDKA. "We always knew he was going to get better."
"But under the circumstances of what the doctors told us, we just decided to go ahead and do it while he was still with us."
Christine Swidorsky carried Logan down the aisle. His grandmother cradled him in her arms, his favorite brown teddy bear by his side.
"This is our dream come true, all our family together, and we're all together celebrating. The celebration of my son's life and the celebration of our marriage," Swidorsky said, as Etta James' "At Last" played in the background.
Fighting since birth
Born on October 22, 2010, Logan weighed just three pounds. Eating troubles kept Logan in the hospital, but he kept fighting, kept growing, and was soon home with his parents and his two older sisters.
And for his first year, he grew, he was healthy, and he made his family unspeakably happy. Even today, as his life nears an end, Swidorsky struggles to find words to say what an amazing little boy he is.
Just after Logan's first birthday, Swidorsky noticed that he wasn't feeling well again, and his lips and fingernails had turned white. Over the course of a month, she took Logan to the pediatrician four times before the head pediatrician tended to him. When he did, he quickly called 911.
Swidorsky said Logan shocked doctors at Children's Hospital of Pittsburgh. His leukemia had progressed so far, they were surprised he was still alive. Chemotherapy was started right away, taking an extraordinary toll on his body.
The couple learned more devastating news shortly after: Logan has a genetic disorder called Fanconi anemia, which most frequently results in death, most commonly from cancer, between the ages of 25 and 30.
But Logan fought hard, just like he had done as a newborn. He landed in the ICU but pulled through, and by July 13, 2012, doctors were prepared to give him a blood stem cell transplant.
After his stem cell treatment, he was free of leukemia for nine months, eating and acting like any other child. Life started to feel normal for Logan's family.
But Swidorsky's gut feeling returned when she saw Logan acting strange again.
It was cancer again: a mass the size of an orange on Logan's larger and better-functioning kidney. Doctors had no choice but to remove the kidney, just a week before Easter this year.
Life gained a long-sought-after normalcy for Logan and the family, except for the twice-weekly visits to a clinic for his chemotherapy. The therapy, though not a perfect solution for Logan, would hopefully prevent a recurrence of the cancer, despite being a lower dose than average.
Logan's life continued to improve.
"He was eating bowl after bowl" of spaghetti, Swidorsky said. "It was a wonderful feeling."
But then he started getting fevers and throwing up.
Logan's left side swelled as the mass returned, where the kidney once was.
"I thought he was doing so well. It's like you take two steps forward, 15 back," Swidorsky said.
The doctors told Logan's family that they could only do more harm than good.
In June, as the family's fortunes continued to fail, the Make a Wish Foundation treated them to a trip to Disney World.
But after just four hours there, Logan was back in the hospital.
Eight days of torture ensued, as he had developed an infection and eventually needed to be flown home to Jeannette, about 40 minutes from Pittsburgh.
Finally, on July 26, doctors gave Logan one to two weeks to live.
Not giving up
But that doesn't mean Logan's parents are giving up.
"We're just blessed everyday that he's here with us," Stevenson said Saturday, after the ceremony. "We're not going to stop fighting. We have nothing to lose.
"I'm going to try until God says otherwise."