Vayeishev: Tzidkat haTzaddik: Natural Urges

All natural things are doing God’s will. So, when a person does natural acts, which he must do according to his nature, it too, is called, “going to do the will of his Maker,” and such an act is a mitzvah.

This includes eating and drinking and intimate relations, which are all natural, just as they are in animals which have no free will, so long as it is a matter of necessity, such as eating when you are very hungry, and intimacy when your nature demands it of you.

An example of this is with Judah, where the rabbis said, “He wanted to pass by the harlot, Tamar in disguise, but the Holy One, blessed is He, sent to him the angel who controls sexual urges (Genesis Rabbah 85).”

So, following your nature is considered doing the will of God and a mitzvah, when it is a matter of necessity, your nature forcing you to it, but only if your intention is that you are doing it because your Maker willed it so and created you this way, with these urges (Tzidkat haTzaddik #173).