Why has he blocked me from seeing his Snapchat stories?

Guy I work with ( we are friends and have had a fling for a few months) has blocked me on Snapchat stories and that is fine but he has left other mates we work with to see them - that’s how I found out innocently. He is currently on holiday with his partner (their open relationship) I am aware of this and our thing is not exclusive and never would be. But we’re friends and we also sleep together so why would he block me? It’s not like he has anything to hide…I am aware of the situation.
Why has he blocked me from seeing his Snapchat stories?
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