Is there anytime in the Bible when God allowed a homosexual relationship?
The Bible begins with God's outline for marriage and family. He starts that way because it is very important to Him. It is through a proper understanding of the marriage covenant and family unity that we have a glimpse of God's love for us and the covenant He made with us.
The Bible very clearly defines what is allowed between a man and a woman and also what is disallowed between members of the same sex. "Do not lie with a man as one lies with a woman; that is detestable" (Lev. 18:22 and 20:13). First Corinthians 6:9-11 says that people practicing homosexuality will not inherit the kingdom of God unless they are cleansed through Christ. You can read further about this issue in Genesis 19; Romans 1:18-32; 1 Timothy 1:8-11; and Jude, verse 7.
Remember, it is the homosexual act, not the homosexual person that God detests. Even Jesus was tempted by the devil in the wilderness and He overcame that temptation. That is what God is calling every person struggling with homosexual desires to do. First Corinthians 10:13 says, "No temptation has seized you except what is common to man. And God is faithful; he will not let you be tempted beyond what you can bear. But when you are tempted, he will also provide a way out so that you can stand up under it."