Stephen Griffiths had been seeing Zeta Pinder for almost two years before he let her step inside his home for the first time.
What she found there horrified her so much that she immediately wanted to end their relationship.
Shelves carrying hundreds of horror films, books about serial killers and the sight of a crossbow and samurai swords in the living room made her feel "really scared" and desperate to leave.
She ended the relationship over the telephone as soon as she arrived home and did not see Griffiths again.
Ten years on, Mrs Pinder was watching the news when she saw her ex-boyfriend had been arrested on suspicion of murdering three women in Bradford.
Forty-year-old Griffiths has now admitted killing the women.
Mrs Pinder, who now lives in Richmondshire, thought Griffiths lived with his parents until she found out he had a flat in Bradford.
He agreed to take his girlfriend there the next night.
Mrs Pinder said what she found inside the flat was "horrific" and "very macabre, very scary".
"You walked in and on the left-hand side there was just a huge bookcase and it was just full of horror books on like the Moors murderers and Jack the Ripper, the Yorkshire Ripper," she said.
"But not just five or six books, literally hundreds of books, and he always had lots of videos... really horrific video nasties."
Mrs Pinder said Griffiths also had samurai swords on the wall and a crossbow leaning against his television, and when she questioned him about them he said: 'I just like stuff like this'.
She said: "It was like somebody else's flat, it was like it didn't belong to him at all. It was just horrific.
"I just got a feeling where I just didn't feel safe so I made an excuse. I said: 'Stephen can you take me home I just don't feel well, I feel sick'."
Mrs Pinder met Griffiths through a lonely hearts column in a newspaper and they had their first date in a local pub.
She said: "[He was] very charming. He brought a photograph of himself which he gave me straight away, said he's had them done professionally.
"I was just laughing and joking with him and called him a poser."
Mrs Pinder said the couple enjoyed a "normal, typical relationship", but she did find some of Griffiths's behaviour disturbing.
She said: "He had a thing about horror films. But he'd think they were funny, the really horrible slasher horror films.
"And when somebody got murdered he'd just like laugh his head off and he'd go: 'Oh great, look at that.'
"He was absolutely terrified of insects crawling in his ears in his sleep so he had to plug his ears with cotton wool.
"One night I didn't have any and he just stayed up all night, he refused to go to bed, wouldn't lie down, which looking back is really quite bizarre."
Of the moment she found out Griffiths had been arrested Mrs Pinder said: "It was just jaw dropping, I just couldn't believe it.
"I cried for quite a bit. It was just such a shock, actually going out with somebody that could actually do that to them poor women.
"I said to my husband 'I hope to god that's not the crossbow I touched that he killed them poor girls with'."
Mrs Pinder said Griffiths had been "kind, caring, loving" throughout their relationship.
"I think the only time I was really scared with him is when I went to his flat," she said.
"And then thinking back about what he did... I think did I have a lucky escape, you know, and I think I did."