After finishing my first part-time job, I ended up joining a house party that also served as a welcome party. It was four of us: my senior coworkers Ryo-kun and Yuki-chan, and Airi-chan, whom I fell in love with at first sight—two guys and two girls. My heart raced at the perfect chance to get closer to Airi-chan. Once the drinking started, we got really into talking about work and love stories. Then suddenly, Yuki-chan whispered to me, "I like Ryo! You like Airi, right? ...Why don't we help each other out?" Then Yuki-chan suggested a king's game. While everyone was drunk, we hugged and kissed, and I even got to kiss my beloved Airi-chan. But I chugged to liven things up and passed out. When I woke up... an unbelievable scene unfolded. On the bed, Ryo-kun and Airi-chan, whom I had fallen for at first sight, were already flirting and starting to have sex! Airi-chan's soft big tits, erotic kisses... Even though I was sad and frustrated, for some reason I got incredibly hard. Yuki-chan, who was sleeping next to me, also woke up, and we both felt restless. Then Yuki-chan noticed my frustrated hard-on and, driven by jealousy, secretly started giving me a blowjob. Driven by mutual frustration, we had an emotional, desperate sex that felt so good I ended up giving a huge creampie. Then Ryo-kun and Airi-chan saw us! Yuki-chan stole Ryo-kun and went from intense kissing to sex. Airi-chan's erotic switch was also flipped, and she forced my dick, which had just come, back to erection with a slurping blowjob, then fiercely fought back with a cowgirl position that made her big tits jiggle. The four of us ended up swapping partners and fucking wildly, developing into a massive orgy where we indulged in pleasure. I even creampied my beloved Airi-chan multiple times, and everyone came like crazy—it was the best welcome party ever. "Let's do it again with the four of us~!"