The first time it happened I had no idea.
I was dressed as a naughty nurse. John came as a surgeon. It was too good to be true.
Looking sexy in green scrubs with tattoos down his neck, a lip piercing and a layer of rough stubble, John had me hooked.
Watch: Emotional versus physical affairs. Post continues after video.
Pressing his body up against mine, we made out on the dance floor. But his wandering fingers left me wanting more.
Back at his place, we fooled around in bed, before I fell asleep in his arms.
By the time I got back to mine the next day, I was bursting with excitement (and sexual frustration).
Desperate to know more about him, I looked him up on Facebook.
And then I saw the truth: 'John is in a relationship.'
I stared at the screen in disbelief. He’d kissed me. He’d taken me home. He’d invited me into his bed.
I felt sick to my stomach.
I messaged him right away. "You have a girlfriend??"
He shot back some excuse about not realising that I would see his relationship status. That the girlfriend was new. That he wasn’t sure if he was even into her.
I didn’t eat it up, but I didn’t stop talking to him either. And he continued to message me.
A week later, he called me on my birthday, asking what I got and what I was doing to celebrate.