Louis is the first male to publicly speak of alleged sexual abuse by Kelly. He was charged in a separate case and pleaded guilty in February to one count of attempting to bribe a witness.
Kelly is not charged with having a role in the attempted bribery, and Louis testified Monday that Kelly was not aware of the plan.
Louis took the stand to describe a more than 10-year relationship with Kelly that started at a McDonald's drive-thru when he was a high school aspiring rapper and ended sometime in the year after Kelly's 2019 arrest, when Louis decided to cooperate with federal prosecutors in their case against the singer.
His testimony came in the third week of Kelly's Brooklyn federal trial on racketeering and sex trafficking charges. Kelly has pleaded not guilty to all charges.
An attorney for Kelly, Thomas Farinella, had no comment on Louis' testimony when contacted by CNN.
A Maybach at a McDonald's drive-thru
Louis testified he met Kelly in 2006 while working at the drive-thru of a Chicago-area McDonald's during his senior year in high school, saying a driver and Kelly pulled up in a Maybach and eventually handed the teen and a co-worker slips of paper with Kelly's phone number.
Louis testified he gave the number to his mother, who eventually called Kelly and told him her son was a big fan, an aspiring rapper and "would love to work with him on (his) music."
Kelly invited Louis, his mother and stepfather to a party at his home and studio in the Chicago suburb of Olympia Fields, Louis testified, and Louis was later invited to Kelly's studio multiple times. Louis said he rapped for Kelly and even recorded a song in Kelly's studio.
One day when he was still 17, Louis said, Kelly invited him to his house, where the singer asked him what he "would do for music." Kelly then asked whether he had any fantasies, specifically about "you and men," to which Louis responded that he did not. He testified that Kelly unzipped his pants and started performing oral sex on him.
"I wasn't into it and I was not getting a reaction, so he had stopped," Louis testified. "He had told me to keep it between me and him."
Louis continued to contact and meet up with Kelly, he said, sometimes for parties at the singer's home, and sometimes to watch Kelly play basketball near the McDonald's where he worked.
When asked by Assistant US Attorney Elizabeth Geddes why he continued to spend time with Kelly, Louis testified, "Because I really wanted to make it in the music industry."
During another visit to Kelly's house, Louis said, the singer took him to a detached garage where he had a boxing ring and exercise equipment. He testified Kelly snapped his fingers and a "young lady" crawled out from under the boxing ring.
"She crawled over to (Kelly) and gave him oral sex. He told her to do me the same way she did him," Louis testified. He also testified he didn't "mind" oral sex with the "young lady" if it had been just between the two of them.
Louis testified he had multiple "sexual encounters" with Kelly, but it was unclear from his testimony whether all of those alleged incidents took place when he was 17. He also testified that Kelly recorded many of the incidents on a camcorder or iPad.
"As our relationship got stronger, he called me more like a brother -- I was his little brother," Louis testified.
A cooperation agreement
In August 2020, Louis was arrested and charged by Brooklyn federal prosecutors with attempting to bribe a witness to stop cooperating in the case against Kelly.
That witness
testified last week in the trial as a former girlfriend of Kelly, identified only as "Jane." She alleged Kelly sexually abused her when she was 17, luring her into his orbit with promises of helping her musical career.
Louis pleaded guilty to one count of attempted bribery and entered into a cooperation agreement with prosecutors, he testified Monday.
In his testimony, Louis said he offered the witness money "to not cooperate" with prosecutors.
During cross-examination, defense attorney Deveraux Cannick emphasized that Kelly has not been charged in connection with the attempted bribe Louis was a part of, and pressed Louis on why he attempted to bribe the witness.
"I was trying to help that person, I was trying to help myself as well," Louis testified. "I was going to get a certain part of the money and I thought that person might have some tapes on me as well."
Louis testified Kelly was not aware of the plan, and said he was not certain where he would get the money for the bribe.
Louis began cooperating with prosecutors on the day he was arrested, he testified, and said he now faces 15 years in prison, but will likely get a letter from prosecutors urging for little to no prison time.
He testified he has not given on up his dreams to make it in the music world, but he was worried that testifying at this trial will affect his career.
"It will affect me -- my reputation -- in a bad way," Louis testified.
When asked by a prosecutor what Kelly -- who had allegedly promised to help him as an aspiring high school rapper -- had ultimately done for his career, Louis responded: "Nothing."