LEBANON, Ohio — O'Brien Jarrett walks to the corner of the room with his two sons. This is the picture area, where balloons and gold letters are pinned to the wall.
A photographer encourages them to smile.
“Do I have to tickle you?” O'Brien said.
His 9-year-old is laughing by now. But a few photos later, Jarrett tickles him anyway. His older son, who plays football in college, asks his dad if he noticed how his T-shirt is fitting.
“I’m going to have to go XL,” said Khy’Lek Jarrett.
They laugh, huddled around the photographer and her camera. In response, O'Brien asks if his son saw how his arms look, and they laugh again.
Days like this almost make Khy'Lek forget his father is in prison.
WATCH: Go inside a Lebanon prison in the video
“If we’re in a regular visit, he can only do so much,” Khy’Lek said. “But with this, it’s like he’s a normal human being.”
The 19-year-old is talking about a recent father-son event at Warren Correctional Institution. First, there’s lunch. And then the families make terrariums together. Neither Jarrett nor his sons have done that before.
“It almost got in my eye,” said Giovanni Jarrett, while dumping dirt into a vase. “We’re making a mess all over the place.”
More than 2 million children in America have a parent behind bars — and most of them never visit, according to a nonprofit that studies our criminal justice system. Inside this Lebanon prison, one local organization is working to change that.
“Parenting is hard — really hard. It’s hard on the outside,” said Jill Hartford, chief operating officer for the Four-Seven, a group that works inside prisons all over Ohio. “I just want to give people the opportunity to be a parent to their child.”
Because those kids didn't do anything wrong, she said.

At the event, which lasts two-and-a-half hours, one of the volunteers starts crying when I ask about his son.
"My son is everything," said Glen Doepel, who started volunteering at prisons in the '90s.
Doepel’s son started the Four-Seven. The nonprofit tries to help people who are incarcerated when they get out. But that work starts inside — where events like this help them maintain family relationships.
“It gives them hope,” Doepel said.
And it's better than a phone call, something O'Brien tells me he does every day.
"I spend a lot of money on the phone," O'Brien said.
Inside his terrarium, Giovanni blows sand off a small plant. And when they're done, even his brother agrees Giovanni's is better.
"This is fun," Giovanni said.
He gives his dad a hug. And before he leaves, he tells him something else.
“I love you."
