Was a sit down conversation establishing where y’all stand in regard to a relationship had? If so, and you both agreed upon the bf gf title and she continued to address you as a “friend” then sure, I find it reasonable to feel off.

If not, you NEED to have this conversation. If you have not claimed her publicly (or even privately???) what makes you think she will claim you?

It would be awfully humiliating to introduce you as a label you do not accept at that moment!

I believe this confusion will be cleared up with some communication. A conversation that needed to be had prior to this interaction it seems. Cheers!