How do you talk to girls?

Women actually tend to be [i]very[/i] alert to the fact that most men who interact with them at length are likely to at least be entertaining the possibility of getting into their pants. If they are already in a relationship, they will generally find a way to bring it up naturally in conversation at the first opportunity to clarify your prospects of any of that as soon as possible.

As for the second part, the moment where that's "admitted" generally isn't of much significance. The relationship is what it is regardless of what you're calling it.

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