1 Corinthians 7:2 – 9
New International Version (NIV)
2 But since sexual immorality is occurring, each man should have sexual relations with his own wife, and each woman with her own husband. 3 The husband should fulfill his marital duty to his wife, and likewise the wife to her husband. 4 The wife does not have authority over her own body but yields it to her husband. In the same way, the husband does not have authority over his own body but yields it to his wife. 5 Do not deprive each other except perhaps by mutual consent and for a time, so that you may devote yourselves to prayer. Then come together again so that Satan will not tempt you because of your lack of self-control. 6 I say this as a concession, not as a command. 7 I wish that all of you were as I am. But each of you has your own gift from God; one has this gift, another has that.
8 Now to the unmarried and the widows I say: It is good for them to stay unmarried, as I do. 9 But if they cannot control themselves, they should marry, for it is better to marry than to burn with passion.
From BibleGateway.com: http://www.biblegateway.com/passage/?search=1 Corinthians 7:2-9&version=NIV