1 Corinthians 7:2-3, 5

But because of [the temptation to participate in] sexual immorality, let each man have his own wife, and let each woman have her own husband. The husband must fulfill his [marital] duty to his wife [with good will and kindness], and likewise the wife to her husband.

Do not deprive each other [of marital rights], except perhaps by mutual consent for a time, so that you may devote yourselves [unhindered] to prayer, but come together again so that Satan will not tempt you [to sin] because of your lack of self-control.