Sexual attraction is different than lust. The first is good as such because it leads to procreation; the second is a vice, an excess of sexual appetite that darkens the mind and, like all vice, corrupts you from the inside. So ultimately, it is best not to "fall in lust". Lust will lead to misery in a relationship precisely because it is the condition where sexual pleasure is sought for its own sake; the other is reduced to an object of sexual exploitation. Because lust is sexual appetite that is no longer proportioned to reason, someone "in lust" will grow tired of his or her partner and will look for the next, often increasingly more risque thrill. Quite a miserable way to live.

Romance as such is also different from lust. It is sexual in nature, but with a greater emphasis on the affective than on just sexual attraction on its own. Romance is what people often mean when they say "fall in love". Typically, romance only lasts a couple years, hopefully having gotten the couple far enough to procreate. Of course, it is possible to cultivate romance, but the main point here is that relationships are supposed to mature, and clinging to the pleasure of passing emotions experienced early in the relationship and using that as a standard against which the relationship is constantly measured is a sign of immaturity.

Love is something we often seem incapable of understanding. Love is not an emotion as such, even if lovers experience emotions. Ultimately love is a desiring and a willing of the good. Love can be broadly divided into two basic varieties, namely, the erotic and the agathonic. The erotic (which should not be understoodd as sexual only) is a desire of the good for one's sake. Whenever we desire something for our own good, we are speaking of erotic love. Agathonic love is desiring the good of the other for their sake. A relationship requires both.