Why does he acknowledge me as “someone”?

Guy I’ve been seeing acknowledges me as “someone “ when he’s on the phone. Like if he is on the phone and someone asks what he’s doing he will say “I’m chilling with someone” he never says my name or says the girl I’m seeing he just says “someone”

Or if his coworkers call him he will say “I’m going out with someone later i can’t come in for extra hours” he never says who i am why?
Why does he acknowledge me as “someone”?
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