A HR expert has warned of the FOUR things you should not do at your work Christmas party - including "complaining about work, pay or managers"."

Melissa Stone, 44, - a HR professional with more than 20 years of experience - says it can take years to build up your reputation at work but one night to undo it all.

She warns workers not to be "fooled" by the false sense of security of a simple night out, because "what happens at the Christmas party does not stay at the Christmas party"."

Melissa, an executive career coach & HR director, from County Wexford, Ireland, said: "It's that time of year again, and for many people, the Christmas Party is the one night they truly let their hair down with colleagues they usually only see during working hours."

"But don't be fooled into a false sense of security by the promise of a simple night out, because what happens at the Christmas party does not stay at the Christmas party."

"Not in 2025, in the age of smartphones, screenshots, and HR polices that apply just as much outside office hours as they do at your desk."

"Every January, HR cepartments deal with the fallout from decisions made after two glasses too many. Reputations are damaged. Career progress stalls - and in the most serious cases, jobs are lost."

She said a few drinks always lead to oversharing, whether that is ranting about your colleagues, having an emotional outburst, or saying you hate your boss.

To avoid any oversharing that might get you in front of HR, Melissa is warning people not to overindulge in alcohol and alternate with non-alcoholic drinks.

"A few too many alcoholic drinks and suddenly people say things they would never say at work, like oversharing personal information, arguing with colleagues, and having emotional outbursts," Melissa said."

"People remember your behaviour, even if you don't. "

"The truth is that if you're going to lower your inhibitions and blur those boundaries, you run the risk of your colleagues losing respect for you, your manager rethinking your judgment, and causing permanent damage to your reputation."

Melissa said behaviour that matters at 10am still matters at 10pm, and colleagues shouldn't make inappropriate jokes or romantic advances.

She added if you think certain comments of behaviour wouldn't be appropriate in the office, they are still inappropriate at the party.

Melissa said: "Everyone knows workplace standards apply at work, but many forget they apply at the Christmas party too. "

"Things can all go wrong quickly when flirtatious behaviour unintentionally crosses boundaries, when touching or dancing is too close for comfort, or when even a consensual kiss under the mistletoe is misinterpreted as something more.  "

"As an HR director, I've seen how one alcohol-fuelled moment at a Christmas party can lead to a formal investigation, and, in some cases, someone losing their job after a harassment allegation."

"If you wouldn't pursue it sober in broad daylight, don't pursue it after midnight with a drink in your hand, even consensual situations can backfire, so take ownership and address things quickly if you feel an apology is in order."

The Christmas party can sometimes feel like the perfect moment to say what you really think.

But Melissa urges anyone not to use the party as an opportunity to vent about colleagues, management, pay, or other conditions you're unhappy with.

She said: "The Christmas party can sometimes feel like the perfect moment to say what you really think - it's not. "

"Don't use the party as an opportunity to vent about colleagues, management, pay, or other conditions. You really never know what might be overhead or what could be repeated afterwards."

"Show up with a positive mindset and interact in a way you'd want people to remember for all the right reasons."

Melissa's final bit of advice is that people will be taking photos and videos that you can't control.

She said you should act like someone who knows Monday still exists, and start 2026 with your reputation and your work relationships intact.

"Every person at the event has a camera in their hand, and the party mood can make people trigger-happy," Melissa said."

"People may not remember you dancing on a table or being silly, but if there's video evidence and WhatsApp groups (or worse, on social media) to share the clips in, they don't need to rely on their memory."

"Even if you think it's harmless at the time, you might not feel the same way in the cold light of day!"

"Although you should never, ever share videos of someone without their consent, you should assume every moment of your life can be recorded and shared by others. "

"So have fun, be friendly, but remember where you are, because even though Christmas parties are fun and a great chance to relax with colleagues, they are still workplace events."

Four things you should not do at your work Christmas party
- Getting too drunk and oversharing, or arguing
- Inappropriate jokes, comments or romantic advances
- Complaining about work, pay or managers
- Photos and videos you can't control