[S1] This inevitable disappointment of erotic lovers means that they rarely remain in a relationship for long.
[S2] However, because erotic lovers often have an idealized image of beauty that is unattainable in reality, they are especially sensitive to the physical imperfections of their lover.
[S3] Instead, they go off in search of another, more ―perfect‖ lover.
[S4] They are easily disappointed by a nose that is too big, a complexion that is too blemished, or a figure that is a bit too full.
[S5] In fact, erotic lovers strive to understand their lover as fully as possible.
[S6] Erotic lovers, like Narcissus, who fell in love with the beauty of his own image, focus solely on beauty and physical attractiveness.
Which sentence comes third?