There are unisex single cubicle toilets at work. I walked in on a male colleague who was sat on the loo looking at his phone. When we locked eyes I heard a splash as a poo hit the water. I quickly left, apologised etc. He also shouted out apologies. The locks on the toilet doors are a bit tricky. But see him all the time and both of us mortified!! Any tips on how to regain our working relationship?