OP teaches that Heavenly Father begat spirit children, indicating belief in HM.
Orson Pratt, "The Redemption of the Earth—Pre-Existence—Marriage.," Journal of Discourses, 26 vols. (Liverpool: Albert Carrington, 1872), 14:242
As our Father and God begat us, sons and daughters, so will we rise immortal, males and females, and beget children, and, in our turn, form and create worlds, and send forth our spirit children to inherit those worlds, the same as we were sent here, and thus will the works of God continue, and not only God himself, and His Son Jesus Christ have the power of endless lives, but all of His redeemed offspring.