A pair of young cousins are both dead following what cops are calling a murder-suicide that was livestreamed at a St. Louis birthday party.

Kuaron Harvey, 14, and Paris Harvey, 12, were live on Instagram around 2 a.m. Friday when a gun that the younger child was playing with went off and killed her cousin — prompting her to then shoot herself, CBS News reported.

Police initially described the deadly incident as a murder-suicide — but their family says it wasn’t so.

“It was no murder. It wasn’t a suicide,” Paris’ distraught mother, Shinise Harvey, told the St. Louis Post-Dispatch. “It was a freak accident. It happened.”

She said relatives who saw the video said the pair was “trying to be too hip” when the shooting happened.

Police told the outlet that the cousins were found unresponsive at 2:07 a.m. and both were later pronounced dead at the scene.

“It wasn’t a situation where they were arguing or anything like that,” said Susan Dyson, the dead girl’s grandmother. “They were playing with a gun when they shouldn’t have been. Of course, they shouldn’t have been doing it.

“I think it just went off,” Dyson said. “It went off by mistake.”

She said the two were at a birthday party for younger family members when they went into the bathroom to film in front of a mirror. That’s when the tragedy happened.

The family said the two were so close they were like “brother and sister,” and typically horsed around when together, pulling pranks, rapping, or making videos.

“No matter how good we raise our kids they still are going to venture off,” Shinise Harvey told the Dispatch.

St. Louis police have not released the results of the department’s investigation.