1 Corinthians 7:2-4

But marriage exists to prevent fornication. It is a step towards chastity. The ideal is to rise above all physical union of the sexes. Perfect chastity is a higher condition than the married state, and the intercourse of married persons, of husband and wife, is condoned and allowed, not commanded. I would that all men had reached the condition with regard to these questions that the spirit has conferred as a gift on me; but, as it is, we must have marriage, and those that are married must follow its rules. Husbands and wives, you are not masters of your own bodies. Each must do as the other has a right to demand in this important matter