A man was caught cheating on his girlfriend with a family member after a tracking app was set up on his phone.
Stan Stockton-Price, an offshore worker had set up the GPS device and had paired it with his girlfriend Milli Hansen's phone so she could pinpoint him out at sea.
However, blundering Stan, 24, had forgotten to deactivate his device once he had returned home, which exposed a secret liaison with his cousin Jess Gifford, according to the Daily Mail.
Speaking to Geraldine McKelvie and Jack Falber at the Sunday Mirror, 20-year-old Milli has spoken of her shock following the discovery.
She said: "I'll never trust a man again after what he did. I was so shocked - no one ever expects to see that."
The shop assistant agreed to look after Stan's younger sister so both he and his mother could go to a family party.
However she became worried when his mother messaged her to say he had not turned up to the gathering.
Remembering the tracking system that had been set up on his phone, she followed it to his Stan's aunt's house.
It was then she caught Stan in the act with his cousin Jess.
She said; "I looked through the window and all I could see was stands clothes strewn all over the floor.
"Then I caught the sight of Jess topless - with Stan beneath her.
"Their faces were a picture when I showed up at the door but I felt sick".
Stan and Milli, from Grimsby, Lincolnshire had been together for two years after meeting at a party through mutual friends.
The pair quickly became inseparable with Stan setting up the tracking device on his phone so they could feel closer than ever even while he was working on wind turbines in the North Sea.
On the day of the family party, Stan had at first decided to stay at home so he and Milli could babysit together while the rest of the family celebrated her 50th birthday party at the local town hall.
As the day progressed Milli noted that Stan "looked like he really wanted to go" and a few hours later he left for the party.
However her suspicions were raised when he went wearing scruffy jeans and a T-shirt while everyone else attending the party was dressed up for the occasion.
When she texted Stan and received no response, Milli messaged his mum who replied that she thought he was with her babysitting.
Remembering the tracking device that had been set up, Milli followed her then-boyfriend's location to his aunt's house at a nearby housing estate.
At first she was relieved and assumed he was simply picking up party supplies.
But her relief quickly changed to horror when she looked through the window and when she banged the door, Jess answered wearing her dressing gown with Stan standing behind her looking guilty.
After she called Stan's mum to come back from the party she stormed off and has not been in touch with Stan since.
Milli added: "After all this, I really don;t think I could put my trust to any guy again."
Stan responded saying: "Of course I feel bad, but I can't change what's gone on.
"One thing led to another and things just escalated."
Jess added: "Natural feeling came over both Stanley and I and we simply acted upon them."