Just because the Bible mentions a trait or act of an individual (even a godly person) does not necessarily mean that the scripture endorses such behaviour. For exmaple, the Bible describes Noah becomming drunk and disgracing himself, his behaviour was hardly condoned.
The Bible clearly gives God's intent for marriage and sexuality. God created our bodies for Him, not so that we can do with it whatever we want. God's will is that no one would use their body in any way contrary to His plan;
I Corinthians 6:13
The body is not meant for sexual immorality, but for the Lord, and the Lord for the body."
I Corinthians 6:20
"Therefore, honor God with your body."
When asked about marriage and divorce, Jesus said in Matthew 19:4-6;
"Haven't you read," he replied, "that at the beginning the Creator 'made them male and female,' and said, 'For this reason a man will leave his father and mother and be united to his wife, and the two will become one flesh'? So they are no longer two, but one. Therefore what God has joined together, let man not separate."
The proper, Biblical definition of marriage is described as a man, leaving his father and mother, uniting to his wife; so that two can unite as one, one man, one women.