For many married couples, sporadic sex is the norm. It shouldn’t be that way and, biblically, it can never be shrugged off as no big deal. Infrequent lovemaking serves as a red flag to mark that something’s gone wrong. Regular sex between a husband and wife is normal.
The husband should give to his wife her conjugal rights (goodwill, kindness, and what is due her as his wife), and likewise the wife to her husband. For the wife does not have [exclusive] authority and control over her own body, but the husband [has his rights]; likewise also the husband does not have [exclusive] authority and control over his body, but the wife [has her rights]. Do not refuse and deprive and defraud each other [of your due marital rights], except perhaps by mutual consent for a time, so that you may devote yourselves unhindered to prayer. But afterwards resume marital relations, lest Satan tempt you [to sin] through your lack of restraint of sexual desire. (I CORINTHIANS 7:3-5, AMP)