Their mile-wide grins said it all.
Knox had nearly 100 percent of the votes while Roeser had 80 percent, says Camille Dorrell, the teacher who counted the votes.
“I cried,” she tells PEOPLE. “I was just amazed our student body could have done this out of the kindness of their hearts.”
They are both “very outgoing and eager to please,” says Dorrell, who teaches them skills like cleaning and cooking.
“Seth loves music,” she says. “His favorite song is ‘We Are Family.’ Kelsey loves Justin Bieber, One Direction and Disney princesses.”
Their fellow seniors were equally excited for the pair, who have gone to school with them since kindergarten.
“Every single day I walk into the room and Seth is singing a song,” Student Body President Kirsten Keers told the Indianapolis TV station.
“And it doesn’t matter if you are having a bad day or a good day,” said Keers, 18. “He’s going to make you smile.”
Roeser is equally sweet, she said.
“Kelsey is going to come up to you and give you a hug,” she said, “or try and talk to you and hold your hand.”
The school has two homecomings – one in the fall for football and one in February for basketball. The couple was crowned at halftime.
Afterward, Knox said he liked it “a lot” while Roeser said it made her “happy.” Their mothers were equally touched.
“When he first started school, I worried about the bullying and all that stuff,” Angie Jones, Knox’s mother, told the TV station. “It didn’t turn out like that. Everybody loves him.”
Roeser’s mother, Jolene, fought off tears.
“For this group of kids to accept these special-needs kids,” she said, “you can’t put that into words, what that means as a parent.”