The elf girl continually cries and screams, struggling uselessly every now and then, and to her horror, discovers that she's beginning to enjoy it. It hurts a little less, despite the stretching of her inner walls, as her own moisture begins to make everything a little slippery, making the ride easier. It's a simple matter for the draconic overlord to tell though, that although her body is reacting like that, and though she might enjoy the physical pleasure, there's still pain, and the fear and humiliation.