CHESTERFIELD COUNTY, Va. (WRIC) — A Pittsburgh firefighter arrested at a Chesterfield Chili’s following a child sex sting used a messaging app popular with tweens and teens.

Federal court documents show the obscene encounter began on social media. Brian Kosanovich thought he was meeting up with a Chesterfield mom and her 10-year-old child for sex. Kosanovich was greeted by the FBI outside the Chattanooga Plaza Chili’s, however.

The mom and daughter he thought he was talking to was really an FBI agent with their Child Exploitation Task Force.

Neighbors in the Pittsburgh area told ABC-affiliate WTAE, they were shocked. One neighbor said, “He never came out, he never bothered nobody. I never seen no women go over there though.”

According to the FBI affidavit, the firefighter and agent spent two months communicating on social media. The interaction began on the fetish website and then continued on the messaging app Kik.

Court records obtained by 8News detail when the agent posing as a Chesterfield mom told the firefighter her daughter was just 10.

Following the admission, Kosanovich typed: “Ok, I’m cool with that.”

In another documented message, Kosanovich, who now thinks he’s talking to the 10-year-old asks, “Maybe we can all play together?”

Kosanovich’s neighbor told WTAE he couldn’t believe it. “That is so crazy,” he says, “because I have a 10-year-old daughter. Thank God I keep eye on her.”

8News has uncovered the Kik app, which is popular with tweens and teens, has been a common factor in at least two other child sex stings in February.

Last week, Jeffrey Hood of Newport News was busted for allegedly using the Kik app to get pornographic photos of children. That same day in Tennessee, a former school principal Mark Pickel was charged with child sex crimes after allegedly using Kik to attempt to meet up with a kid who turned out to be an undercover agent.

“At the end of the day they are still children, so it is OK to take the phone and look at it,” said Stephanie Davis, coordinator of the Greater Richmond SCAN Child Advocacy Center.

8News asked Davis what can parents do to keep their kids safe?

“The most important thing is really going to be that communication and understanding what they are using,” Davis said. “So, if they are using an app and you don’t know what it is, download it, figure it out.”

Davis adds that if you spot a concerning conversation, talk to your child.

“I think the first thing is to ask the child: “How do you know this person? Where did you meet them from?”

If there is something alarming, Davis says report it to the authorities. She also recommends banning the phone in the bedroom at night, suggesting that kids’ phones should be charged overnight in their parent’s room.

Stephanie Davis, coordinator of the Greater Richmond SCAN Child Advocacy Center.

“That way that kid is not feeling like they have an ongoing need to connect with everybody,” Davis said.

The National Center For Missing And Exploited Children offers NetSmartz, an online safety education program. The site offers guides and tips for smartphone and social media safety.

As for Kosanovich, the Pittsburgh Public Safety Department calls the charges “disturbing.” They say in part, the firefighter has been “removed from duty and placed on unpaid administrative leave pending an administrative investigation.”

Kosanovich is being held at the Pamunkey regional jail in Hanover county.