Why does a girl hide her IG stories with her Boyfriend from a guy?

I have talked with this girl a lot previously... for about 4 years... even if we didn't meet in person.

Currently she still reacts to my stories... even if... she has a boyfriend... ( as she hides the stories... I suppose I shouldn't know about her and her boyfriend ).

I recently moved with my job really close to the city from wher she is from
Why does a girl hide her IG stories with her Boyfriend from a guy?
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