Amber Davies claims to have been bombarded with messages from women claiming they've slept with Kem Cetinay.
The "Love Island" star split from her boyfriend in November and she can't believe the "Dancing On Ice" contestant has been speaking about how heartbroken he is and his struggle to get over the break-up, when she thinks he's private behaviour suggests otherwise.
She told the Sun on Sunday newspaper: "I felt like I'd been stabbed, but Kem was saying he was bleeding.
"I've had a handful of messages from girls - some sent just a few days after we had split - saying they had slept with him. Others have been from people claiming their friends have slept with him.
"People deal with things in different ways, maybe that was his way. But if I was sleeping with loads of people, I wouldn't speak publicly about how heartbroken I was."
Amber has been romantically linked with singer Olly Murs and "The Only Way is Essex" star Pete Wicks since her split from Kem, but she insists she's happily single and finding exercise the best way to get over her heartache, thanks to the launch of her new fitness programme Strong Not Skinny.
She added: "After we split up I was straight into party mode, but behind the scenes I felt very anxious. So after Christmas I started going to the gym with a personal trainer friend.
"That helped me feel better and it lead to me launching Strong Not Skinny."
Kem recently claimed he was "gutted" by reports linking Amber with other stars.
He said: "I'm not going to lie when I say that it does really hurt. I am gutted. It does make me sad. It is hard to see.
"I am not going to sit here and say it is fine - I still have feelings for her - but at the end of the day, if she wants to date a celeb then I have to accept it. There's nothing I can say."