He didn't do anything "again". It is clear from Genesis 20:12 that Sarai was BOTH Abrams's sister and his wife, his Father had multiple wives and she was his half sister:
Gen. 20:12 And yet indeed she is my sister; she is the daughter of my father, but not the daughter of my mother; and she became my wife.
Sure he did. Can you not read and understand?
He GAVE HER AWAY TWICE!