It doesn't help that you can see she's getting more and more turned on herself....
As she moans, she keeps saying loudly: "That's it! Cum for me! Let it all out!"
You are torn between obeying Faye and Sydney, but the faster Faye fucks you the more certain you are that you are going to cum quickly. You desperately try to hold back, but all the while you feel more and more helpless...