You can't stop it

Erica continues fucking you at full speed, doing absolutely nothing to prevent you from going over the edge. You grit your teeth as you use all of your might to hold back what you know is coming. It's ultimately useless, as another jab from her fake cock pushes your cock deeper into Olivia, a wave washes over you. You begin to tremble as you feel your cock spewing inside of your tied up girlfriend.

"OOOOOOOHHHH!" You moan as your body collapses fully onto her.

Erica continues thrusting for a moment before noticing your lack of motion.

"Did you just cum?" Erica asks, her voice stern and sharp.

"I couldn't help it." You breathily plead. She shoves the cock into you again, this time harder than ever before, causing you to jolt up. She holds her position.

"That is no way to respond to me." She scolds. "The only correct way to answer is with Yes Mistress, or No Mistress." She says. You can feel her attempting to push the dildo in deeper even though it clearly has nowhere else to go. "Now, let's try that again. Did you just cum."

You do your best to gather your thoughts as once again all you can think about is the pain in your ass.

"Y..yes" You gasp

"Yes what!?" She snaps.

"Yes Mistress." You whimper, feeling close to tears. She finally pulls back, allowing you to relax slightly.

"I am very disappointed." She says. She's no longer in as deep, but still deep enough to keep you firmly in place. "Not only did you cum without permission, but you defiled this Goddess with your seed, and for that you will have to be punished."

You definitely don't like the sound of that. You let out a long stuttered breath as you anxiously wait to here your fate.