How do guys let their male friends know that they don't value them as a friend and/or colleague?

For example, I've heard that during a meeting, a male supervisor may ask a certain employee what their opinion is, and then right after the employee shares their opinion, he will ask if anyone else has an idea, so as to imply that her opinion doesn't matter to him. Apparently male employees pick up on this signal, and either try to improve their work performance so that their supervisor values their opinion, or they take the hint to find another job. Do guy friends do that too to each other?

How do guys let their male friends know that they don't value them as a friend and/or colleague?
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