Sacred matters require Spiritual understanding, and do not follow the laws of mortality, nor are they to be discussed lightly nor irreverently. Our Heavenly Father is the father of both the Spiritual body and the mortal body of Jesus Christ.
James E. Talmage writes:
"Mary's promised Son was to be "The Only Begotten" of the Father in the flesh; so it had been both positively and abundantly predicted. True, the event was unprecedented; true also it has never been paralleled; but that the virgin birth would be unique was as truly essential to the fulfillment of prophecy as that it should occur at all. That Child to be born of Mary was begotten of Elohim, the Eternal Father, not in violation of natural law but in accordance with a higher manifestation thereof; and, the offspring from that association of supreme sanctity, celestial Sireship, and pure though mortal maternity, was of right to be called the "Son of the Highest." In His nature would be combined the powers of Godhood with the capacity and possibilities of mortality; and this through the ordinary operation of the fundamental law of heredity, declared of God, demonstrated by science, and admitted by philosophy, that living beings shall propagate--after their kind. The Child Jesus was to inherit the physical, mental, and spiritual traits, tendencies, and powers that characterized His parents--one immortal and glorified--God, the other human--woman."