Omar Mateen's alleged gay lover said the Orlando shooter acted out of "revenge." Getty Images

Omar Mateen, the man linked to the deadliest mass shooting in modern U.S. history, did it for “revenge,” a man who claims to have been Mateen's lover told Univision on Tuesday. The man, who kept his identity secret, said he had multiple trysts with Mateen from October to December 2015 at a hotel in Orlando, Florida. The man, who wanted to be called “Miguel,” concealed his identity through prosthetics. Univision altered the tone of his voice to further conceal his identity.

While Mateen pledged his allegiance to the Islamic State group in a Facebook post before the June 12 massacre that killed 49 people, Miguel claimed the killing spree was prompted by a threesome. Mateen feared he contracted HIV when he discovered one of the men had the virus, Miguel said. But even though Mateen tested negative, he was afraid the results were not accurate, Miguel said. As a result, Mateen wanted to “make them pay,” Miguel said, according to Britain's Daily Mail.

Miguel said he decided to speak up after reports that the slaughter might have been politically motivated. “The thing that makes me want to tell the truth is that he didn’t do it for terrorism,” he said. “In my opinion he did it for revenge.”

Miguel described Mateen as a heavy drinker and a confused gay man. At first, he didn’t known Mateen was a husband and father. The shooter was attracted to Puerto Rican men, but felt rejected and used by them, Miguel said. “He hated gay Puerto Ricans for all the stuff he did to him," Miguel said. "I believe this crazy horrible thing he did was for revenge."

When they first met, Miguel said their date was normal. He described Mateen as a man who “loved to be cuddled. ... He loved to be embraced.” They often had sex and Mateen seemed “adorable” and “sweet.”

They would have rendezvous at the Ambassador Hotel in Orlando. Miguel’s story was confirmed by a representative of the hotel, who said Mateen stayed there at least 60 times last year. Miguel said they met via Grindr, a dating app for gay men. He labeled their relationship as “friends with benefits.”

Though Miguel claimed he spoke with the FBI about his relationship with the shooter, a law enforcement official would not confirm or deny it. Both men and women told the FBI they were in relationships with Mateen and the FBI is investigating all those claims, CBS News reported Tuesday.

While it’s conceivable Mateen carried out the assault as an act of terrorism, former senior FBI profiler Mary Ellen O'Toole said it was unlikely. "This to me suggests somebody that may have had sexual identity issues and may have actually been struggling with the idea that he himself was gay and that would add a different motive and a different perspective on the case," O'Toole told CBS News.

At least 49 people were killed and 53 were injured at Pulse nightclub when Mateen opened fire.

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