You struggle mightily to obey her. You close your eyes again, and bring to mind Faye's tits.
This gets you even more aroused, as Faye's tits fill your whole imagination. You struggle to not cum as you feel your sperm ducts loosening even more and pre-cum dripping more freely...
You know you have to say something or this will never end. Finally, you say that her tits are more triangular than Sydney's, and less rounded...