So your view is that once she became pregnant, by God, she was disenchanted with mortal man, and would never consider having relations with he husband?
This is the wrong approach and the wrong question. In order to understand this you have to look at the larger picture. This includes what we can deduce about Mary from scripture as well as what we can learn from the OT scriptures and Jewish OT practices.
The following is taken from an article
PERPETUAL VIRGINITY OF MARY by Br. Anthony Opisso, M.D.
"In Jewish Law a man betrothed to a woman was considered legally married to her. The word for betrothed in Hebrew is Kiddush, a word that is derived from the Hebrew word Kadash which means “holy” “consecrated,” “set apart.” Because by betrothal (as in Mt 1:18; Lk 1:27) , or marriage, a woman became the peculiar property of her husband, forbidden to others.
The Oral Law of Kiddushin (Marriages and Engagements) states; “The husband prohibits his wife to the whole world like an object which is dedicated to the Sanctuary” (Kiddushin 2b, Babylonian Talmud).
We know from the Gospel of Matthew 1:14 that Joseph the husband of Mary was a righteous man, a devout law-abiding Jew. Having noticed that Mary was pregnant and that he, her betrothed, had nothing to do with the pregnancy, Joseph had either to publicly condemn her and have her put to death for adultery (Dt 22:22-29) or put her away privately.
His decision was made when an angel appeared to him in a dream, saying: “Joseph, son of David, do not fear to take Mary as your wife; for that which is conceived in her is of the Holy Spirit; she will bear a son, and you shall call His name Jesus, for He will save His people from their sins” (Mt. 1:20-21). The angel does not use the phrase for marital union: “go in unto” (as in Gn 30:3, 4, 16) or “come together” (Mt 1:18) but merely a word meaning leading her into the house as a wife (paralambano gunaika) but not cohabiting with her. For when the angel revealed to him that Mary was truly the spouse of the Holy Spirit, Joseph could take Mary, his betrothed, into his house as a wife, but he could never have intercourse with her because according to the Law she was forbidden to him for all time.
Marriage to the Holy Spirit
We also have to take into consideration that when Mary was told by the archangel Gabriel “Behold, you shall conceive in your womb, and bring forth a Son, and you shall call His name Jesus” (Lk 1:31), he also added that this was to come about because “The Holy Spirit will come upon you, and the power of the Most High will overshadow you; therefore the Holy one to be born shall be called the Son of God” (Lk 1:35).
By stating it in those terms the archangel declared to Mary that God would enter into a marital relationship with her, causing her to conceive His Son in her womb, For “to lay one’s power (reshuth) over a woman” (Targum to Dt 21:4) was a euphemism for “to have a marital relationship with her.”
Likewise “to overshadow” (Lk 1:35) by spreading the “wing” or “cloak” over a woman was another euphemism for marital relations. Thus, the rabbis commented (Midrash Genesis Rabbah 39.7; Midrash Ruth Rabbah 3.9) that Ruth was chaste in her wording when she asked Boaz to have marital relations with her by saying to him “I am Ruth you handmaid, spread therefore your cloak ( literally, “wing”: kanaph) over your handmaid for you are my next-of-kin” (Ruth 3:9).
Tallith, another Aramaic-Hebrew word for cloak, is derived from tellal = shadow. Thus, “to spread one’s cloak (tallith) over a woman” means to cohabit with her (Kiddushin 18b, see also Mekhilta on Exodus 21:8). Did not the Lord say to His bride Israel: “I am married to you” (Jr 3:14) and “your Maker is your husband”? (Is 54-5:5; Jr 31:32)? And what is more intimate than what the Lord said to His bride: “You developed, you grew, you came to full womanhood; your breasts became firm and your hair grew… you were naked… and I saw that you were now old enough for love so I spread my cloak over you… I gave you My oath, I entered into a covenant with you and you became Mine, says the Lord God” (Ezk 16:7, 8).
cont. on next post: