"When you fall for someone like that, you've in a very intense relationship, the feelings never completely go away," the reality TV star confessed.
Despite not being totally over Spencer, she wasn't afraid to say what she really thinks of him and described him as "selfish".
"I'm very protective of myself and I know what's good for me – I thought it was him and it's just not," she revealed to Look magazine. "I'm stubborn in that and I'm going to stick by what's right.
"He's quite a selfish person and he thinks about what's good for him and I think if he was me he'd do the same."
Lucy is dating again but admitted she isn't looking for anything serious.
When asked if she'd consider taking Spencer back, Lucy laughed the idea off.
"I'd go Spencer 'get up', and just own it and get over it," she said.
Spencer admitted he cheated on Lucy during the show's End of Season Party and admitted that he was "out of control".
"I've slipped up," he said. "I've cheated on her. It was pretty recently, a couple of days ago. I was in Greece. I think I'm just young and living some form of dream but unfortunately hurting people in the process."
The couple had been together for two months before his infidelity, which took place during a trip to Zante with his best friend and former MIC castmember Hugo Taylor, who cheated on then-girlfriend Millie Mackintosh during an earlier season of the show.