When a Sigma male feels and internally knows something is up about a female he used to be interested in, he intellectually pulls away with respect. He doesn't disrespect her. He doesn't act nasty.
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The Sigma males heart and mind becomes detatched and he quietly moves on with his life. Why? He has bigger fish to fry in being futurely "primetime."
He also allows the man she's possibly-currently involved with to have his personal way with her, because the Sigma male knows how to mind his business.
And when that Sigma male sees the man face to face that he feels is involved with the woman, he knows the spiritual rule about "following peace with ALL men," and to greet him respectfully as a brother.