Is she really just a friend of my boyfriend?

Found a message on my boyfriends phone from a woman that he was planning on having dinner with. He never told me about her. Says they had a few dates in December before we became official. They both don’t want to date each other because of various reasons. He said they are only friends and didn’t tell because he didn’t think it would be a big deal. Then he told me that he’s not dating anyone else. They just have dinner and most of the time go their separate ways.
Is she really just a friend of my boyfriend?
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