You never expected this.
Someone had told Stiles that you were cheating on him with Derek.
Of course it wasn't true, you'd never cheat on your boyfriend. You loved him more than anything.
Derek had ever so kindly let you use the loft to hold Stiles a surprise birthday party. He even was helping you set up.
"Be careful on that step ladder," he warned. You let out a laugh as you pinned the balloons on the wall.
"I don't know why Stiles calls you sour wolf, you're not that ba-" you cut your self off with a small scream as your foot slipped. You fell to the side and straight into Derek's open arms. He held you there for a moment as you caught your breath back.
"Are you okay?" Derek asked as you let out a relieved breath. Before you could reply, Derek turned his head to the right, making you do the same. Your mouth dropped at the sight of Stiles standing there, wide eyed. He looked like he was tearing up.
"So it's true." Was all he could muster up, his voice was quiet and shaky. Derek let his arms drop to his sides and you quickly took a few steps towards Stiles.
"What is true?" You asked, feeling totally confused,
"Happy birthday to me." He mumbled to himself as he looked at the floor.
"I thought you'd like it.." You answered quietly, as you looked around. You thought he was talking about the surprise birthday party. Immediately Stiles' eyes met yours, you noticed a single tear roll down his cheek as his body began to shake.
"You thought I'd like to find out that the rumours are true?" He asked, his voice raising. You felt so confused.
"Stiles?" You asked as you stepped forward. "What are you talking about?"
"You y/n!" He shouted as more tears escaped his eyes. "You and him!" He pointed at Derek who put his hands up in a surrender motion.
"What about me and Derek?" You asked, your voice suddenly sounding laced with anger.
"How could you cheat on me with him, y/n?" He asked as he ran a shaky hand through his thick brown hair. "You can drop the act, I know the truth now. I saw you," he paused as his eyes trailed over to Derek. "In his arms."
Derek stepped forward, he walked past you and put his hand on Stiles' shoulder who quickly shook his hand off and stepped away.
"What you saw was me catch your girlfriend as she slipped off the step ladder while putting up balloons for your surprise birthday party, Stiles." Derek explained before he patted Stiles on the shoulder and walked towards the open door. Stiles stared at you and you couldn't read his face.
"Stiles, I would never cheat on you. I-i love you." You told him, your voice breaking mid sentence. Stiles stepped forward and quickly nodded as he took you into his arms.
"I know.." He breathed as you cried on his shoulder. "I'm going to kill Isaac!"
