Why does he repeat random things I say as I'm talking to him?

When my crush and I talk he tends to repeat some things I say. For example I told him I was doing yoga and then the kept repeating yoga multiple times. Another time I told I had class Wednesday nights and then he kept repeating Thursday. Today I told him I pull all nighters and he kept repeating all-nighters. Its all random things that he is repeating. Why?
Why does he repeat random things I say as I'm talking to him?
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