The 32-year-old singer recently went public with her relationship with 25-year-old bullfighter and professional trainer Alex Fine, but a source tells ET that Diddy feels betrayed by Cassie after finding out that she allegedly cheated on him with Fine, whom Diddy actually hired for her as a personal trainer, as well as paid for.
However, according to TMZ, who was first to report the news, sources connected to Cassie and Fine insist the two didn't start dating until after she broke up with Diddy.
Prior to the new drama, Cassie and Diddy's breakup appeared friendly and even had some fans believing they would be getting back together. The two have been romantically linked as far back as 2007, and last January, the father of six even said he was open to having more kids with Cassie during his appearance on The Breakfast Club.
“Without a doubt, I love children,” he said. “I could go to eight without a problem. Can’t stop, won’t stop. Whatever is supposed to happen in the future is going to happen, but that’s something that I want.”
“I would only have it with my girl, of course,” he added.
Though by October, a source told ET that the two had broken up. Although there were rumors that Diddy was dating 26-year-old model Jocelyn Chew, the source said that the 49-year-old mogul actually wasn't dating anyone at the time.
Cassie herself paid tribute to Porter on Instagram and praised her ex as "the best father" in the process.
“There are no words,” she wrote alongside a black-and-white photo of Porter. “An amazing mother to her beautiful family, lit up every room she entered and now the most beautiful angel 💔 Sending so much love and my condolences to the Porter and Combs family. I love you @quincy, @kingcombs, Jessie, D’Lila, Chance, @princejdc and @diddy. Puff you are already the best father. I know you will be amazing. Love you too.”
As recently as late December, it appeared Diddy was attempting to reconcile with Cassie. The Bad Boy Entertainment founder took to his Instagram Story to share an intimate photo of Cassie smiling in a hot tub -- adding a heart emoji -- which he posted twice.
But the very next day, Cassie went public with Fine. Cassie shared a photo of the two kissing, as well as one of Fine posing with her and her mother at a party.
Fine is no stranger to the celebrity world. The elite trainer, who has his own personal training program called Alex Fine Performance, has a number of A-list clients including Jennifer Aniston, Kelly Ripa, as well as Riverdale stars KJ Apa and Charles Melton. He also trains professional athletes including NFL stars Odell Beckham Jr. and Reggie Bush.
"I built my gym on friend referrals. And that has to do with results," Fine told The Manual last June about his incredible success. "People get the results they want or need and I get them there in a short amount of time. It’s also about trust. What they tell me, I’m not going to repeat. I’m not an Instagram trainer. At the end of the day, it’s about results."
Meanwhile, on Wednesday, Diddy shared a pointed video on Instagram of a motivational speaker who spoke about getting rid of toxic people in the new year.
"2018 was designed to show you who everybody is," the speaker says. "God has to reveal character, motive, intent, heart posture, plans, schemes, plots. He had to show you people, even people who you thought were for you, he had to show you that they weren't for you -- they were for them, as long as you could help them. They were for you, but when you weren't for them, they weren't for you."
"And God had to expose that, and it's painful to see people you invested in, spoke life into and believed, now they've shown who they are, and it's because God needed it to happen this year, because they could not come into 2019," the speaker continues.
These days, it appears Diddy is now focused on his family. On Thursday, he shared a heartwarming picture of his mom hugging his 12-year-old twin daughters with Porter, D'Lila Star and Jesse James.
"GOD IS SO GOOD. THE GREATEST!!!" he wrote. "I’m the luckiest man in the world. The way my family has been strong has humbled me. They have led me. They brought me out of a state of deep depression. Their strength and love brought me back into the light. I love my family!! 🖤 THANK YOU GOD @CombsFamily #MamaCombs @the_combs_twins @myfancychance.