Properly done, flirting with customers can be fine. But most men don't know how to properly flirt.
First, they confuse flirting with "hitting on". Those are two different things. But the main thing about flirting is that you sneak up on it. You start with interactions that are friendly and 99% innocent. The sort that will not offend or threaten anybody. If you get responses in kind, you gradually escalate. If you don't, or if they stop, then you stop as well.
In a way, flirting is more like a dance. If your partner isn't dancing with you, you need to stop doing it with them.
First, they confuse flirting with "hitting on". Those are two different things. But the main thing about flirting is that you sneak up on it. You start with interactions that are friendly and 99% innocent. The sort that will not offend or threaten anybody. If you get responses in kind, you gradually escalate. If you don't, or if they stop, then you stop as well.
In a way, flirting is more like a dance. If your partner isn't dancing with you, you need to stop doing it with them.