Why is this guy butting into my conversations?

There is a guy I like ( he knows i like him) , and lately was starring at me so intensely during my groups presentation in class. It got kinda overwhelming with how much he was staring at me. He also also of the last 3-4 conversations I’ve had with guys he will observe, then butt in and include himself in our conversation. Just curious what some thoughts are?

Why is this guy butting into my conversations?
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