Soon, Anders is in to the root, and Nathaniel's tongue works him for a moment before his head begins bobbing up and down. It's something of a trick; Anders, like most men, is longer when aroused, so Nathaniel must adjust a bit as he goes on. Still, he enjoys him very much, though he isn't really aroused at all himself. There's more to this than sexual gratification. It's intimacy and a show of affection. One of many expressions of love Nathaniel has learned from this man. Those fingers are in his hair and massaging his scalp, and Nathaniel feels pinpricks along his back from it. There is trust and understanding, a sharing of bodies transcending any sense of self-preservation. No, Nathaniel does not need sexual pleasure in order to love this.