What does Genesis 28:9 mean?

So Esau went to Ishmael and married Mahalath, the daughter of Ishmael (Abraham's son and Isaac's half-brother), in addition to his other wives. Genesis 28:9 - Modern Text Bible

(Trying to fix things, Esau marries a woman from Abraham's extended family, hoping this will please his parents. It's a bit of a last-minute attempt to fit in.)