David McIntosh used to "bully" Kelly Brook when they were together.
The former 'Gladiators' star reportedly used to tell the model she was "fat" during their seven-month relationship last year and shattered her self-esteem by insulting her lips.
A source close to Kelly revealed: "All her friends know David is a nasty piece of work but people outside have no idea what he's really like.
"He treated her appallingly.
"He'd tell Kelly she was fat, he'd bully her. She's a beautiful girl but he threw all sorts at her. He said she had no lips, which got to her."
The couple - who were engaged to be married - split last year amid rumours the ex-military fitness model had been unfaithful, but Kelly is now feeling much more positive about her life and is currently dating Italian judo champion Jeremy Parisi.
The source told the Sunday People newspaper: "Kelly has a new life and great boyfriend. There are some great projects in the pipeline for her."
However, David - who recently ended his relationship with an Australian jewellery designer who he had been dating - previously said he feels sorry for his ex-fiancée's new love interest.
Asked about her new relationship, he said: "It doesn't really bother me now, but I feel sorry for Jeremy because he looks like a decent lad.
"I think she's more focused on herself and her career. I think she's incapable of having a normal relationship."