Would it be too informal to say " my old fellow" if I was talking to my colleagues?

如果我与同事说话， 我说“老兄”党会不会过于随便?。

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With tears in my eyes, I said, "You're more than welcome, old fellow."

我含着泪水说：“你在这里永远受欢迎，老伙计。”

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I loved my old, job my fellow workers and the company I left.

我热爱我以前的工作、同事和我离开的公司。

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