A Las Vegas man allegedly killed his girlfriend and her two kids after she admitted cheating on him, claiming he “blacked out” before launching his deadly rampage.

Juan Orona, 29, turned himself in shortly after 7 p.m. Tuesday with a gunshot wound to his abdomen, telling officers he had shot his girlfriend, Nohani Flores-Osuna, and her two children, Maiya, 16, and Noah, a kindergartner, KLAS reported.

Orona said he confronted Flores-Osuna at an apartment complex in west Las Vegas after he spotted her car near the vehicle of her ex-boyfriend, identified only as “Henry,” earlier Tuesday, according to an arrest report obtained by the outlet.

Flores-Osuna allegedly admitted she had been unfaithful to him and told Orona that her ex-boyfriend was “better in bed,” he told police.

Orona claimed he “blacked out” and later found himself holding his 9mm Glock handgun in the bathroom, with Flores-Osuna and her two kids dead on the floor.

Police went to the apartment in the 5100 block of O’Bannon Drive, near the intersection of Sahara Avenue and Decatur Boulevard, and forced their way inside, finding the three victims dead.

Orona told police he recalled Flores-Osuna and her children either yelling at him or coming toward him during his blackout, but he could not provide further details, according to the report.

Police said Orona did not deny shooting the three victims, but claimed he could not remember who he shot first or why.

Orona told dispatchers the shooting happened inside the apartment where he had been staying with the family and said the gun was inside a backpack in his vehicle, according to the report.

He was taken to Sunrise Hospital for treatment of the gunshot wound. The report does not say whether the injury was self-inflicted.

The 29-year-old had been dating Flores-Osuna for roughly three to six months and had helped pay the rent for the apartment where the gruesome killings happened.

Orona reportedly told detectives he knew he needed to surrender and be held accountable.

His father told police his son called around 7 p.m. Tuesday saying he had hurt his girlfriend and her children, then accompanied him and Orona’s brother as he surrendered.

At Thursday’s hearing, Orona’s court-appointed public defender asked to delay the bail decision to allow time to review the case, Fox 5 reported.

Orona is facing three counts of open murder with a deadly weapon and 10 counts of firing a gun into an occupied structure.

He is scheduled to return to court Sept. 9 and remains in the Clark County Detention Center.