Was very upset by a colleague and explained why in what I thought was a fair and calm way (checked with another colleague first) the first colleague has now taken offence. Anyone have any experience of this? Will it get better?
I'm sure it'll be fine. there are always tensions in any workplace. I think it's normal and natural anywhere where you have lots of people forced to spend time together. Schools are stressful places too.
Is your colleague going to be feeling horrible? Are they upset that they upset you? If they are just offended/angry and all you did is explain that they'd upset you then I really wouldn't spend time worrying about it. You haven't done anything wrong.
One of the many excellent pieces of advice my NQT mentor gave me was to stay out of the staffroom just before a school holiday. People are tired and end up saying things they don't really mean and so upsetting people/getting upset. So when you go back after half term, draw a line under this and treat your colleague as you would have done if it hadn't happened - put it in the past and give them a chance to put it behind them too. (But be aware of the possibility of the colleague getting upset in the future).