Why is my crush’s brother staring at me a lot?

My crush has a twin brother and they’re super close, I’m pretty sure my crush likes me but i feel like he’s starting to lose interest (I don't know maybe not I have anxiety lol) anyways, I catch his brother staring at me a lot now but he barely talks to me even tho I try being friendly with him, I just think he’s shy but my friend thinks he might be the one who likes me not my crush and now I’m super confused.
Why is my crush’s brother staring at me a lot?
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