Is my gym crush actually into me or the loud, flirty girl instead?

I have a gym crush. We’ve inside jokes, he has given me many compliments looks and personality. We support each other, shared personal things, meaningful moments together. I liked that it seemed to be developing naturally. Recently, another woman at the gym has started seeking his attention much more. She is funny, loud, very present, gives him a lot of validation. I find her behavior intrusive because she comments loudly on my body, clothes, hair, appearance in front of others, though saying I am attractive. She also noticed that he and I had worn matching partner outfits before. After that, she asked him about it, suddenly they wore matching outfits too. I told him I thought that had been our thing. He said she had given him the “order,” but that he and I had our own colors. After that, I pulled back a little. When I avoided a class where they would train together, he suddenly signed up for my class instead. He was attentive, asked if I was okay, reminded me about our next workout together, asked whether we would wear matching outfits again. When we trained together again, he asked if we should get something to eat and drink afterwards. It felt like a date. He asked personal questions, remembered things I had said, complimented me, brought up a shared experience that he described as beautiful and even “romantic.”2 days ago we went to a concert with a small group from the gym, she was there too. She kept finding ways to be near him, like get drinks together, go to toilet at same time. I tried not to compete and focused on enjoying the evening, but it hurt because he seemed energetically more with her. Now she has signed up again for the same classes as him, including one I’m also in. I was signed up first and don’t want to cancel because of her, but I don't know how to deal with their dynamic. It hurts because I keep wondering whether I misread everything. How can a woman with this kind of behavior fascinate him? Do men like that?

Is my gym crush actually into me or the loud, flirty girl instead?
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