We must distinguish those signs that disclose the sinful lust. The physical movements are natural in the body and there is no sin in them. Sin is when the man relates in a wrong way to them, with his freedom and conscience. The man who finds delight in these movements, arouses them willingly and is ready to satisfy them lusts.
The one who by satisfying this lust frequently gets the inclination to seek its pleasures suffers of passionate lust that troubles him and torments him tyrannically. In this situation it takes control of the whole man and this man begins to lead his life in accordance with the circumstances that may feed and arouse this lust. Because of the sweetness brought by the satisfaction of this passion, it is called the passion of voluptuousness.
Because of its ruining action against the soul and body, the Apostle calls it `wicked lust` (Colossians, 3,3) and considering the humiliation of the understanding being `opprobrious passion` (Romans, 1,26)
Saint Teophanus the Recluse, Questions at the questions of the intellectuals, Sofia Publishing: Alexandria : Orthodox Book, vol.2, 2005-2007, p. 49.