Cuckolded by 18 Year Old Girlfriend

I felt absolutely gutted as he knelt between her thighs and I watched the back of his head trace figure eights over her pussy. I listened as she whimpered and moaned, grabbing his head with her fingers and pushing his tongue firmer onto her clit. I felt my cock growing harder and harder, cum rushing and my temperature rising. I was so jealous, I strained against the ties but it was no use. She didn't care, she was wrapped up in his mouth and the pleasure it was making her feel.

I tried closing my eyes to block out the scene playing before me, but it didn't help. I wanted to watch. I'd never seen any sex acts live before, never been in a gang bang in college, and this was something I struggled to comprehend. I wasn't watching just any live sex, but my girlfriend. This was my sexy little eighteen year old girlfriend that I'd taught how to fuck, and here she was exploiting my most secret fetish on my birthday. I hated to love it as I heard her whimpers, watched her face contort and saw her chest rise and fall as she built to an orgasm. Watching her legs shake and quiver as she moaned and came was torture of the hottest kind.

The new guy then rose and lay down on the chaise section of my sofa, and my girlfriend straddled him. She turned to me, poked out her tongue cheekily and winked for a split second before she began to sit down on his big, hard cock. I saw exactly how the wet little lips of her pussy slid over his cock, and as he thrust in and out of her, her wetness left a mark on his shaft.

Watching as he went balls deep inside my girlfriend, I felt a huge competitive rush of cum flood my balls. I was so turned on and so jealous at the same time that it fucked with my head. Hearing her moan and exclaim "Oh, yeah, fuck, fuck me harder, yeah," made my cock swell beyond the point I thought it could. I felt wet, glistening pre-cum run down the head of my cock as I watched each thrust of his cock inside her.

They stopped for a moment, and my girlfriend leaned down and appeared to be whispering in his ear. They then moved to the edge of the bed, right near me. I could almost touch my girlfriend with my leg when he bent her over and began ramming his cock into her from behind. With one hand he rubbed and squeezed her perky breast and little pink nipple, pinching and playing with it softly.

Watching this made my blood boil at the same time as more pre-cum rushed from my cock head. With his other hand he rubbed her clit and mound, kneading it in circular motions. I saw my girlfriend's wetness as it coated the inside of her thighs, the wettest I'd ever seen her. Her face was twisted in an expression of absolute pleasure. She moaned and whimpered and gasped with each thrust.

"Fuck, oh my god, yeah, make me cum," she moaned in a low voice before biting her lip as she started to orgasm. "Oh my god, fucking hell, yes, god yes," she exclaimed, bucking her pussy and hips back against his firm shaft.

He groaned and I recognised that sound from the video - he was about to cum. I felt a flash of rage and desperation as his cock started to pulse and cum inside of her. His hands dropped and grabbed her hips so he could angle his cum deeper against her cervix.

He stepped back and kissed my girlfriend firmly one last time before walking to the pile where his clothes lay and putting them on. My girlfriend, however, ignored her clothes. She instead moved up the bed like a confident lioness, and in one smooth motion, removed my gag and placed her pussy over my mouth.

My mouth was still open from the gag being removed, and the new guy's thick cum fell to the back of my mouth. It tasted not too dissimilar from mine, but thicker, which just made me angrier. I ate her cream pie, every last drop that I could manage, and stroked her swollen clit with my tongue to finish. My entire mouth tasted of his and her cum mixed together, and a part of me wanted to wash my mouth out with straight whiskey immediately. I heard the bedroom door shut, and my girlfriend moved herself back off my mouth and knelt with her glistening pussy hovering over my hard cock.

"How did you like your birthday cream pie?"

"Get on my dick."

"Not until you tell me just how delicious that surprise birthday dessert was."

I stayed silent for a moment. I needed her to fuck me or I felt like something inside me that was already fractured by this experience would break into a thousand pieces.

"It tasted good."

"Are you gonna say thank you?"

"Thank you."

She laughed. "You loved it, don't lie. You were practically humping the air. Look how hard you are. But anyway, that was only part one of the present."

"Oh Jesus. What else can you do?"

"I can do this," she said cheerfully, before untying my feet and then my hands.

With no thought, just reflex, I flipped her over like she was weightless and fucked her until the sun came up.