Alicia stops him just in time

"Max, wait!" cried Alicia suddenly, "you can't cum inside Blake!"

"Huh?" Max grunted. He barely heard what she said as he was so focused on the pleasure of fucking you. What the fuck was Alicia doing!?

"Why not?" said Simone, "It's not like she's the first girl to get creampied this evening."

"Yeah!" agreed Kay, her hand on her own sperm-filled pussy, "you even let Max cum in you." She looked back over to you and Max, "I think he should cum in her. I bet she'll love it."

"Oh god yes!" you moan in response to Kay's words.

"No, you don't understand!" Alicia was frantic, "she's not really my cousin! She's... he's... that's Blake! that's OUR Blake!"

"What?!?" Liz nearly spat out her wine.

Fuck! Why was Alicia doing this? She's blowing your cover and right when Max was about to fill you with his seed! "Max, cum in me, please!" you cried. Max grunted in confusion and pleasure but he kept fucking you.

"She doesn't know what she's saying," Alicia said, "Look, Blake came to me this morning. He said he wanted to come to this sleepover but he didn't think any guys would be allowed in! So we got one of those X-Change pills so he could sneak in as a girl!"

"Oh, I've heard of those!" Kay perked up. She checked out your body as Max continued thrusting into you. "Damn! Those pills really work!"

"Yeah, I tried one once," said Simone, "I was curious what it was like to be a man. It worked great! And I was HOT."

"What!? Get the fuck out of here!" Kay shot Simone an incredulous stare.

"Guys! This is serious! Listen!" Alicia protested, "They were out of regular X-Change pills so Blake took a Breeder pill! It turned him into a girl for 72 hours, but he's super fertile, and if he gets pregnant he'll be a woman forever!"

"Holy shit." said Simone.

"Gnnugh," Max slowed his thrusting and looked you in the face, "Blake, is this true?"

You looked up at your best friend. "Yes Max, it's true," you said. You wrapped your legs around him and pulled him further into you as pleasure enveloped your entire being. "But this is what I want, Max. Fucking you is the best thing I've ever felt and I want you to keep fucking me, and I want so bad to feel you cum inside me!"

"Max!" cried Alicia, "she's only saying that because the Breeder pill is making her try to get pregnant! The pharmacist warned him about that side effect but he figured it wouldn't be problem since there weren't supposed to be any boys here."

"I... I..." Max shook his head as he started fucking you again. You can tell from the pace of his thrusts that he is ready to cum and at the same time you are so close to the edge you can practically taste it. You feel Max thrust deeply into you one last time before you feel him fully withdraw. The sudden empty feeling is quickly followed by a hot wet splashing as Max unloads all over you belly his cum pools in you belly button and matting your pubic hair.

You scream in frustration as you can feel the orgasm that was so close slipping away again. "I was so fucking close!"

"So close to being stuck as a girl forever you mean." Alicia says looking down on your prone form.

"Hmm..." said Sam. "You might not have made her cum, but you definitely made her scream. I think we'll call that mission accomplished in light of the new facts."