A young woman has recalled the moment she discovered her then-boyfriend was hiding a huge personal secret after taking a closer look at a 'haunting' photo. 

When she was 17, Tiffany, from the US, dated a 'tall, gorgeous' boy she met at a rodeo show and the pair were together for nine months. 

But three months in she noticed he would always wear long pants in hot weather and wouldn't let her attend one of his basketball matches. 

After taking a close look at a photo they took together that she realised she had been dating a man with 'one leg'. 

'If you've ever thought you were blissfully unaware, let me tell you about a time I dated a guy for three months before finding out he didn't have a leg,' she said in a TikTok video. 

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In the clip, Tiffany said the two quickly became 'inseparable' and 'fell in love' soon after meeting. 

We saw each other every day, we spent every waking moment together. We were young lovers. For three months, we dated. We were in love... we did love things,' she said. 

Then she claims 'couple of weird things started to happen' that she picked up on. 

'He would show up to my softball games, 32 degree [Celsius] weather wearing sweatpants. I'm like, what a weird fashion choice (but) I didn't say anything,' she said.

'One time he had his arm around me and he was limping. I was like, 'Why are you limping?' and he was like, 'Oh it's an old knee injury'. So I thought, oh okay, that makes sense.'

Then when she asked to go see him play in a basketball game, he said: 'you're absolutely not allowed to come to my basketball games'. 

'I was like, 'Why not?' He said, 'I don't have performance... anxiety... I just don't want you to come',' Tiffany continued. 

'I was like, 'Even if you're the worst on the team, you're like 198cm, you can't be the worst on the team. You stand there and you're better than half the other guys'.'

But he responded with: 'No, I just don't want you to come.' 

One night the couple had a photo taken together before going out to dinner, which eventually helped Tiffany realise why her boyfriend was acting so strange. 

'This picture is haunting,' she said and showed the image in the background of the two standing beside one another smiling. 

'The next day I post this picture to Facebook and the more I stared at it, the more I thought, 'I think I'm being bamboozled'.' 

Feeling confused, she decided to show her friends the photo and ask for advice. 

'I said, 'Guys I think my boyfriend might only have one leg',' she said.

'They were like, 'Why would he hide that from you?' and I was like, 'I don't know. But I don't know how to ask him if he has one leg because like... How do you bring that up?''

In the weeks proceeding the tried to get her boyfriend to 'open up' and talk about what she assumed to be true. 

When the pair attended their prom he finally told her his secret.  

'We had an after-prom house where we'd go to a lake so he was going to have to wear a bathing suit,' she said.

'He took me to a park and was like, 'I need to talk to you about something'.'

He explained he had polio - an illness that causes paralysis - and Tiffany told him she knew something was off.

'I was like, 'Listen, I suspected this for a couple of weeks now and you made it real weird by not telling me',' she said in response. 

'I asked, 'What did you think I was going to do?' He responded, 'I don't know, you met me and you didn't know so I just ran with it'.'

'I was like, 'I guess but three months? You hid it for three months?' I'm that dumb and unaware.'

Despite this, the pair stayed together for 'another six months' then broke up after Tiffany went to college. 

The detailed video has since been viewed a staggering 2.3million times and thousands were left in disbelief. 

Others shared their personal stories with partners who have similar conditions.  

'My husband did the same thing when we first dated. He was afraid I would leave him. We have been together 25 years before he passed from cancer,' one woman wrote. 

'I was with a guy for a year and he had toes missing but I never asked because I thought if he wanted to tell me, he would,' another said.   

Another added: 'I now feel less bad I went through an entire night not realising a girl had one arm. She hugged me and everything.'