Genesis 30:16

30:16 When Jacob came in from the fields that evening, Leah went out to meet him and said, “You must sleep with me because I have paid for your services with my son’s mandrakes.” So he had marital relations with her that night.

Genesis 35:22

35:22 While Israel was living in that land, Reuben had sexual relations with Bilhah, his father’s concubine, and Israel heard about it.

Jacob had twelve sons: