A bar worker of 15 years couldn't understand why she was 'stone cold sober' after downing eight vodkas - only to realise she got the measurements wrong and was having tiny 2.5ml shots thinking they were 25ml.
Kelly Windebank was having a night in with her friend Marie Guinelly earlier this month and grabbed a nearby Calpol syringe to measure out the spirit as she was counting her calories.
But three hours into their evening the 36-year-old couldn't understand how she didn't feel drunk - with the penny finally dropping only when she realised she'd actually been using a 5ml syringe not a 50ml one.
The singleton said the pair couldn't stop laughing at her blunder and worked out that she'd not even drank the equivalent to a single shot of vodka - despite finishing a two-litre bottle of coke.
Marie, 40, shared a photo of a deadpan 'stone-cold sober' Kelly holding her drink glass, empty bottle of mixer and the Calpol syringe to a Whatsapp group where she was branded a 'bloody f*ckwit'.
Kelly, of Portsmouth, said: "I was doing 2.5ml shots. The syringe that they use for Calpol is 5ml and I thought it was 50ml so I'd just do half. We worked it out. I had 20ml, so not even a shot, in three and a half hours and I pretty much drank a two-litre bottle of diet coke.
"We were just in absolute hysterics. I just went in and was like 'you won't believe what I've just done'. We were laughing about it for days after. I just wasn't really thinking. The funny thing is, I do actually work in a bar as well, so that's the ironic part of it.
"Marie posted it on the chat just to rinse me. They were just in hysterics and a lot of them were like 'you work in a bar, I can't believe it' sort of thing."

The 36-year-old said she'd been calculating her calorie intake for around six months and as she was moving home all her utensils were packed up, so just used a Calpol syringe she'd found.
Kelly said: "I'm doing a bit of calorie counting at the minute so have been measuring out my vodka into a jug but I didn't have a measure because I'm in the middle of moving. I thought 'you know what, I'll just use that Calpol syringe, that's 25ml' and I thought it said 25ml. I was about three and a half hours into drinking and I thought 'I feel alright' which was a bit weird.
"I was wondering why I was still sober and thought Marie was trying to top up my jug. I said 'do you keep topping up my vodka because hardly any is going?' and she said 'no, why would I do that?' because I thought she was trying to sabotage my diet.
"I even put the glass on the measuring scales and thought 'I'll have a double', so I put 5ml in and when I put it on the scale I thought 'oh no, what an idiot I was actually drinking 2.5ml of vodka'. I'm just a doughnut basically. We were just laughing so much. But then I did play catch-up so it was alright."
Get the best stories from Wales straight to your inbox by signing up to our newsletter here.