Not showing the groom the bride’s wedding dress is an age-old tradition.

But one bride was left gutted after her pal posted a picture of her in her wedding dress on Facebook and tagged the groom.

The unnamed bride took to Mumsnet revealing that her close friend, whose name also isn’t known, secretly snapped a picture of her during a dress fitting, Daily Mail reports.

The friend then posted the picture on Facebook and tagged the groom.

"I know I probably am sad but just wanted to hear others’ opinions on whether they would be sad about it or if I just need to get a grip!” the bride-to-be wrote.

"Getting married soon and after trying on a lot of different dresses I finally found the one, something I never thought I would due to being very body conscious and anxious.

"Went back for final fitting at the weekend and took one of my bridesmaids as she wanted to see.

"After finishing the appointment and getting home I saw she’d posted a photo of me in the dress on Facebook (during the appointment so it had already been on an hour or two when I saw it).”

When the woman requested that her friend remove the post, she simply shrugged it off, Mirror News reports.

“When I asked her to remove it her response was ‘it doesn’t matter if he's seen it, he's a man so he will have forgotten what it looks like in five minutes time’.

“My dad had also seen it and it was going to be a surprise for him on the day too.

“I just don't know what to do or how to feel! I am so gutted that it now won't be a surprise to my partner or my dad.

“She knew how much that meant to me and the only thing I had asked for was that details of how I will look on the day were kept a surprise from my dad and partner.

“As I paid in instalments the dress is now fully paid for and I don't have time to get another one and do all the alterations etc. Someone tell me I will stop feeling like this soon!” she went on to write.

Fellow users were quick to console the woman, telling her to give her bridesmaid the boot, The Sun reports.

"Sack the bridesmaid! Don't worry, your dress will look different when your hair and makeup are done etc. Try not to let it spoil the day,” one person said.

“I would be furious! I'd be seriously considering if she would be coming to the wedding!” another said.

Source: Daily Mail, Mirror , The Sun