Lucy

I gasped. The front door! Oh god, I tried to push Alex off me but he just swatted my hand away and took me harder.

"AAAAUUGGHHRR" I moaned loudly, before I could stop myself.

"Hello?" I heard my sister say "Alex? Ash?"

She began to turn the corner. She was gonna catch me fucking her boyfriend.

She turned the corner and was greeted with the sight of Alex, balls deep in me.

"I can't believed it!" she cried. However, something was wrong. She didn't sound angry she sounded annoyed.

"Sorry, babe" Alex said surprising calmly. He was still fucking me. Why hadn't he stopped? Why wasn't Lucy freaking out.

"Lucy I…AAUUGGH" I tried but I couldn't speak. I was so shocked my orgasm had stopped building when I heard the door open. But now, Alex's powerful thrusts combined with the shame and excitement of being fucked in front of my sister were gonna send me over the edge.

"You can just be quiet, you slut. How could you let my boyfriend fuck you."

"I'm so…UUGH…sorry" I grunted.

"C'mon Lucy a bets a bet" Alex said.

What?

"Fine, fine you win" Lucy said

"W-what?" I moaned

"UUG…you should probably tell ash what's going on" Alex groaned

"I had a bet with Alex" Lucy said "if he managed to get you to fuck him, I'd let him fuck me in the ass. If he lost, I'd get to fuck him in the ass"

I couldn't believe what I was hearing but that last part sent me over the edge.

"IM CUMMING, AAHH, IM CUMMING!" I screamed. However, instead of finishing me off, I felt Alex's cock pop out of my pussy. I slumped forward "oh, no, no, no, please" I begged as I lay quivering, **** to cum.

"You can cum" Lucy said "if you agree to let me film if"

"Yes, anything" I cried

"You heard her" Lucy said as she got out her phone and hit record.

I felt Alex fill me up again. It only took a few thrusts until my walls clamped down around his cock. I moaned like a whore all through my orgasm. I felt so ashamed as my sister filmed the whole thing.

"Are you happy no…ooooougg" I said quietly before I heard Alex groan and felt a strange warm sensation between my legs. "Did you just…?" I asked.

"I just totally came inside you" he said

"And it's all on film" Lucy added "I never knew my sister was such a cum slut"

I couldn't even respond. I felt so worn down. I just lay on the sofa, feeling Alex's hot seed leaking out of my pussy, forming a pool between my legs. I guess this was one stain on the sofa I did cause.

"C'mon" Alex said to Lucy "I've got to claim my prize"

"Please, just be gentle, I haven't been fucked In the ass before" Lucy begged

"Neither have I" Alex replied "but I can't imagine that you would have been gentle about it"

As I lay on the sofa ready to pass out, the last thing saw was Lucy undressing as she and a still naked Alex run up stairs. This was followed by yelps and moans as Alex fucked my sisters ass, hard.