Yerushalmi Berachos, perek 9, halacha 2, (64A):
Rav Acha taught:
[Earthquakes happen] because of homosexuality.
Midrash Rabah, Parshas Bereshit, perek 26, paragraph 5:
Rav Huna taught in the name of Rav Yosef:
The Generation of the Flood was not blotted out
of the world until they made official marriage contracts