I mean, it was more of a plot device than anything else. He was wrong in saying it doesn’t concern her when it does concern her, in a different sense of the world, because she loves him.
but I don’t think that justifies the fact that she’s trying to concern herself with everything involving him. ishigami is already happy, and was doing well before she was introduced to the manga. love doesn’t justify trying to out someone’s love life, she’s just being annoying at this point
She asked how his date went. When they were in private.
They do my man Ishigami wrong. That's still called butting in and he had the right not to tell anyone.