You did great. He's being childish; you're being the adult. Excellent validation and refusal to escalate. He was probably just mad because you have GAL plans and he's wondering what they are!
11/4/15 W revealed EA/2 months later became PA with co-worker Reconciling since late April 2016 Don't give up until it's time, then move on Be patient, strong and kind but never a doormat
