For some teens, bringing someone from you’re family to a school dance seems like the embarrassing last resort. But for one teen from South Dakota, bringing his 10-year old sister to his high school’s winter formal was a move that showed he was proud to have his little sister in his life.

As People reported, 15-year old AJ Spader took his terminally-ill sister Rebekah to his high school’s dance.

“I would be broken if you weren’t my sister because you taught me how to be brave and I’d be blessed if you went to formal with me,” AJ wrote on a poster he wrote for his sister.

Rebekah was born with hereditary sensory autonomic neuropathy (HSAN), according to KDLT. It’s a hereditary disease that attacks the nervous system. Six years after her initial diagnosis, her family found out she has Myelodysplastic Syndrome, a type of bone marrow failure.

Treatments were undergone, but chemotherapy and a bone marrow transplant didn’t work. So, after realizing that none of the treatments they tried weren’t working, the family has decided to stop treatment all together.

Aware that she has limited time left, Rebekah came up with a bucket list which included a concert that raised $20,000 for Make-a-Wish South Dakota.

Now, big brother AJ is helping her experience something she might not be around long enough to experience: attend a high school dance.

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“I wanted to ask my sister because she’s most likely not going to be able to experience high school. So I just thought why not ask her to formal,”AJ said in an interview with KSFY.

Being 15 and a high school can be awkward and excruciating for any young boy, but AJ is living up to the family motto of “Broken. Brave. Blessed.”

Those words were also the family’s mantra after they learned last year that Rebeka’s transplant did not work.

“It helps you survive,”dad Tony Spader said. “I mean, just realizing the facts, you know, we are broken. The family has been brave.”

Clearly, that bravery has shone through with AJ.

“AJ was able to kind of look past himself and what he would want and try and give her, Rebekah, an experience that she’s not going to be able to have because she probably won’t make it to her high school years,” Tony said about his son.

The prospect of giving his love to a girlfriend is going to have to wait for AJ. The lucky girl can wait. For now, his devotion is focused on Rebekah.

“I want to spend as much time with her as possible while she’s still doing good,” AJ said.