LITTLE Andrew Jackson peers excitedly out of the window and smiles as he sees his dad John in the street. But his little face crumples as he watches him walk straight past and into a house just six doors down.

For fireman John turned his back on his five-year-old son and wife Julie after beginning an affair with Julie's good friend Mandy Clements.

Julie, 39, explains: "Andrew can see it all from our house, so they could at least have the decency to conceal it from him. It broke my heart when Andrew asked why a little girl was in his car seat. And why Daddy was taking someone else to school instead of him.

"If I take Andrew bowling we often see John and Mandy there. Andrew doesn't understand what's going on, now he's terrified he's going to lose me too. He asks: 'When's daddy going to argue with her and come home?' How do you explain that to a child?"

Julie is still shocked at Mandy's treachery and can never forget how she discovered it. Her suspicions that John was having an affair were confirmed when she checked his phone - and found he had stored pictures of Mandy's bum and his own private parts.

He had seemed so different when Julie met him in 1999, when they worked at a petrol station in Worthing, West Sussex. Soon she was besotted.

She recalls: "He was a real charmer. He told me everything I wanted to hear and spoilt me rotten. He was everything my first husband wasn't. He made me laugh and showered me with affection."

He moved into her house and the love-struck pair became inseparable. Andrew was born nine months later in November 2000 and a year after that they married.

"I was the happiest woman in the world," says Julie. "I had a husband who adored me and a beautiful son. We did everything together and Andrew was the apple of John's eye. Life was perfect."

But in October 2002 Julie's dad was diagnosed with throat cancer. She had to turn her attention to her parents.

"John didn't like the fact that I wasn't there to cook his tea and look after his every whim," she says. "He kept telling me I was miserable, but what did he expect? My dad was dying. It wasn't exactly the best time of my life. I expected him to support me. Instead, he did his own thing."

FROM then on his attitude changed. He made excuses to avoid spending time together and began hiding his mobile phone.

"Alarm bells were ringing in my head, but deep down I still loved him," Julie says. "Besides, I couldn't prove anything. Perhaps I was just paranoid." And things improved when former factory worker John followed his dream of becoming a fireman.

"He was on cloud nine and proudly paraded around in his fireman's outfit," recalls Julie. "He was proud as Punch, and so was I. All of a sudden my husband was a pillar of the community. He loved his newfound status. People would stop him in the street and ask about fire-fighting. He loved every minute. And we started getting on better than ever."

But her suspicions were raised again last Boxing Day when John left the house, saying he was needed at the station. She turned to her friend and neighbour Mandy for reassurance.

Julie explains: "Her daughter and Andrew were at the same pre-school, and because she only lives six doors down we used to walk together and chat in the playground. I knew she'd separated from her husband 18 months ago because he'd cheated on her, so I was sure she'd understand.

"I told her John was making excuses to stay away from home and how he'd taken overtime at work. She told me her husband did exactly the same and how hurt she was by his cheating. "I needed a shoulder to cry on and Mandy seemed the perfect person. I opened my heart and told her my suspicions. 'Us women need to stick together!' she said. If only I'd known."

Mandy offered to look after Andrew after school while Julie was working as a dental receptionist, but somehow she suspected something wasn't right. After an argument with John one night she checked his mobile phone. She was stunned to find the last number he'd dialled was Mandy's.

"My jaw almost hit the floor," she says. "Why on earth would my husband be calling Mandy?"

Furious, she scrolled through the photos on his phone - and came across a sordid picture of Mandy's bum. "I could hardly believe my eyes," she says. "But the next photo was even worse. It was a close-up of his private parts.

"I felt physically sick. I imagined him sending it to her with some lurid message. Suddenly the penny dropped. I collapsed in a heap on the floor. I'd been such a fool."

But that evening, as John kicked off his shoes and cracked open a beer, Julie flipped and threw him out. She says: "He didn't bother kicking up a fuss. He'd been caught red-handed. He walked down the street and straight in through Mandy's front door, where he's lived ever since. I couldn't believe how brazen they were."

One day, sick of watching them parade their affair in front of her, Julie knocked on Mandy's front door and slapped her. "I don't know what came over me," she says. "I just wanted to give her a piece of my mind, but when I saw her smug face my anger boiled over. I'm not proud of it."

Now Julie is determined to get on with her life and ignore them. "In a funny way I'm relieved," she says. "I'd been walking on eggshells with John for months, and finally this was my get-out clause.

"But to this day I can't understand Mandy's treachery. She goes out of her way to avoid me. She'd been through it herself, so how could she do it to another woman? I'll never forgive her."

John says: "I don't want to broadcast to the entire world what goes on in my life. Me and Mandy are together, but I'm not living with her fulltime. Julie is conniving against me, but I'm like a rose - I thrive on it. Some of it may be my fault. I just don't care any more. All I want is to see Andrew on a regular basis."

Mandy says: We are togther now. It's not ideal living in the same street as Julie and Andrew but I have to put up with it."

Andrew wants his father to come home and he's terrified he'll lose me too