Speaking to E! News, the 26-year-old claimed she had quit her job with Star magazine after Gosselin promised that he would break up with girlfriend Hailey Glassman in order to be with her.
"I was with the person I was reporting on. He's the one who actually told me to quit my job," she said.
"He told me he was going to Massachusetts to break up with [Glassman]. I know the truth. He knows the truth. Unfortunately, she did not.
"We had plans to travel together, to live together and to be together... He wanted to be with me... He tried to two-time both of us. He wasn't honest with Hailey. He needs to man up and tell the truth. I'm not going to be the other woman."
She added: "I was not the only one who was around when we were romantically involved. We were holed up together. It's not like we were just sitting there doing an interview."
Gosselin has reportedly denied Major's claims that they were involved in a relationship. He announced his split from estranged wife Kate in June.
> Kate Gosselin "shocked" by Jon's romance