What does it mean, when a guy had a crush on me, but then found another girl and they both are trying to get in front of my face as much as possible?

it's a guy from my gym. he has been looking at me for cca past 5 months, but we never talked to each other (sometimes i just went to him to ask some things about gym, but nothing personal). but recently, i went to the gym and i saw him with another girl. as soon as they saw me, the guy said something to that girl and they immediately kissed each other. it seemed like it was on purpose, because of me showing up there. i started to exercise and right after, the guy came next to me, even though they were somewhere else before, and started exercising as well. then his girlfriend came and they started teasing each other. i don't know, but it seemed toxic to me, like if they wanted to show off. i immediately went away, because it was really annoying. i'm not jealous, but i hate the way he acted in front of me. the thing is, he maybe thinks i have a crush on him, but i actually don't. so... what does it mean and what should i do?
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edit: to add to that, the girl was sometimes checking me as well. i assume that she was insecure a bit.
What does it mean, when a guy had a crush on me, but then found another girl and they both are trying to get in front of my face as much as possible?
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