Well, first we show that the Bible claims Christ never sinned, so could not have had pre- or extra-marital relations:
:bible1: “Do you not know that the unjust will not inherit the kingdom of God? Do not be deceived; neither fornicators nor idolaters nor adulterers nor boy prostitutes nor sodomites” 1 Corinthians 6:9
:bible1: “For we do not have a high priest who is unable to sympathize with our weaknesses, but one who has similarly been tested in every way, yet without sin.” Hebrews 4:15
Then we show that Christ was not married. Consider the following passages:
:bible1: “For I am jealous of you with the jealousy of God, since I betrothed you to one husband to present you as a chaste virgin to Christ.” 2 Corinthians 11:2
:bible1: “Be subordinate to one another out of reverence for Christ. Wives should be subordinate to their husbands as to the Lord. For the husband is head of his wife just as Christ is head of the church, he himself the savior of the body. As the church is subordinate to Christ, so wives should be subordinate to their husbands in everything. Husbands, love your wives, even as Christ loved the church and handed himself over for her to sanctify her, cleansing her by the bath of water with the word, that he might present to himself the church in splendor, without spot or wrinkle or any such thing, that she might be holy and without blemish. So (also) husbands should love their wives as their own bodies. He who loves his wife loves himself. For no one hates his own flesh but rather nourishes and cherishes it, even as Christ does the church, because we are members of his body. “For this reason a man shall leave (his) father and (his) mother and be joined to his wife, and the two shall become one flesh.” This is a great mystery, but I speak in reference to Christ and the church. In any case, each one of you should love his wife as himself, and the wife should respect her husband.” Eph. 5:21-33
:bible1: “One of the seven angels who held the seven bowls filled with the seven last plagues came and said to me, “Come here. I will show you the bride, the wife of the Lamb.” He took me in spirit to a great, high mountain and showed me the holy city Jerusalem coming down out of heaven from God.” Revelation 21:9-10
Throughout scripture it is the Church that is depicted as the Bride of Christ. If Christ had a human wife, this understanding would never have come about.