Holding back tears, Andy confirmed to best friend Stevie the reports that surfaced earlier this year about Louise spending a night at Niall's home.
CLICK ON PHOTOS FOR FULL GALLERY
"This guy that Louise had said that she fancies got in touch with her the other day and had texted her asking to go for a drink," he said.
"I thought whatever, she goes for a drink... four hours later I haven't heard from her at all. I texted 'How was your date?' Nothing. It gets to two in the morning, I text 'Where are you?' No reply."
"She was lying and knew she was going to stay the whole time as he sent a car to pick her up and he lives 45 minutes out of London... I'm just gutted, I don't know how she can so casually do it to someone else – she knows exactly what I feel like."
Andy became frustrated after meeting up with Louise, who failed to understand why he was so upset.
"I stayed at my friend's house, I told you," she said. "Do I have to tell you where I am the whole time?"
The meet-up ended disastrously, with Andy walking off and leaving Louise alone in the bar. But the pair made up at a party after Louise's friend Millie Mackintosh, who is engaged to Professor Green, gave her some advice.
Meanwhile, Louise's ex-boyfriend Spencer Matthews and Lucy Watson's relationship seemed better than ever, with the pair seen hugging and kissing at every opportunity.