I want to talk or make a move on my crush but I don't know how to?

Ok so I was scrolling through Instagram randomly stalking someone's following and I saw this very attractive guy. I followed him the very day and we became mutuals. I tried to dig in some information about him and I got to know that he is serious about a girl. He keeps trying to make a move on her. In such a situation, should I start talking to him or just, you know, let it go?

I want to talk or make a move on my crush but I don't know how to?
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