Romans 7:3
So, if she lives with another man while her husband is still alive, she will be called an adulteress [i.e., a person who is sexually unfaithful to their mate]. But if her husband dies, she is legally free to marry another man without committing adultery.
Matthew 5:32
But I say to you, every person who divorces his wife makes her become sexually unfaithful to him [i.e., since she will probably marry someone else], unless the reason for the divorce is that she had [already] become sexually unfaithful to him. And whoever marries a woman who has been divorced commits sexual sin with her [i.e., because she is still rightfully married to her first husband].
Mark 10:6-12
But from the beginning of creation God made mankind male and female.
John 8:3-5
Some experts in the law of Moses and Pharisees brought [to Him] a woman who had been caught committing an immoral sexual act and stood her in the middle of the group.
1 Timothy 5:11-14
But refuse [to put] younger widows [on the list. See verse 9], because when they become restless for sensual pleasure, contrary to [their commitment to] Christ, they want to get married [again].