Evil look

I found the kettle just boiling in thr office kitchen today.  There was a cup with instant coffee and small pots of milk and sugar beside it.  Not wanting to take all the water, i filled the cup before my own.  A colleague appeared and ask if I did that, indicating the cup. I confirmed I had, not wanting to use the water.  They tossed the whole lot into the sink, proclaiming it to be too much water and then that their coffee was in their bag.  I apologised and offered mine but they left, slamming the door behind them.  I met them returning as i headed to my desk and apologised again but they looked the other way.

It felt like a bit of an overreaction to me.