A family holiday is on the verge of ruin after one child was left in a very risky situation.

With summer now here, Brits will be setting off across the globe to soak up some much needed sun. But one dad's idyllic summer getaway has now turned into a nightmare, following his parents did something unspeakable.

The tense drama unfolded when the 35-year-old went away with his wife, their two young children and his parents, who kindly paid for the family's flights. Although he's tried to savour the moment, a worrying safety mishap has caused quite the rift between them.

"I'm currently on holiday with my parents, they invited me and my family to their friends apartment with a pool, and paid for the flights, my mum recently retired," he explained, posting anonymously to Reddit. "[One day my parents] offered to take my daughter to the pool... I watched from the balcony and they played with her... she had fun."

At the time, their daughter – who's only a toddler – was wearing a float vest while paddling around. The dad watched this anxiously for around 20 minutes, acutely aware his daughter and his supervising mother can't actually swim.

The nameless man continued: "My dad who had her in the deep-end seemed to ask her to swim by herself to the shallow end (where she can stand) whilst he got out, grabbed his things and then walked around...

"My wife was completely panicking whilst this was happening and ended up shouting from the balcony which is not like her as she is very unconfrontational. I watched and whistled to get their attention but didn't want to make the situation worse or into something it wasn't... And in fairness, my daughter did manage to 'swim', and then walk to the shallow end where they collected her."

Incredibly, this isn't the first time something like this has happened with the children's grandparents either. On one occasion, the dad claims he walked in to find his infant son wandering 'half way up the stairs'.

And, on a different day, he noticed his daughter's car seat harness had been far too loose because the grandparents didn't know how to fasten it. However, speaking on the swimming pool dilemma, he said: "When they returned they said: 'One little girl safely returned' and I said: 'Yeah just about, you left her in the deep end'.

"They said: 'No we didn't', and at that exact moment my son fell and hit his face on a table... I had to deal with that... how can I re-address this, am I overreacting?"

Unsurprisingly, the anonymous post has since racked up hundreds of comments online, with countless users claiming this is a blaring red flag. Concerned, one person warned: "Behaviour like this is an iceberg. You witnessed them in the pool, but unless you constantly spy on the parents with the granddaughter, then you aren't seeing everything."

Meanwhile, another said: "This particular time wasn't a massive deal maybe but next time who knows what they'll do," as someone else stressed: "Stop letting them have your kids unsupervised!"

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