At one place I worked at (private sector), one of the lady from the sales team would flirt with the guys. She would feel sheepish on the next day for her actions, but everyone would otherwise just get on with things as the rest of the year rolls round. No one perma-offended. I'm not sure why the media pinpoints Christmas do's in particular, although I guess it must be true as we've had birthday do's as well and they all involved alcohol without further ado. People seem to get into more mischief at Christmas time.
It's Christmastime, there's no need to be afraid
At Christmastime, we let in light and we banish shade
And in our world of plenty we can spread a smile of joy
Throw your arms around the world* at Christmastime
*but keep your hands to yourself - no groping