A/N: In my headcanon, Blaine and Cooper are brothers by marriage. Just wanted the reader to know :))!
Blaine looked around the place his dad and new stepmom were having the after party at. It looked like any typical venue, a place where sweet sixteens and bar mitzvahs would be held. He saw a couple of his more eccentric relatives already ordering drinks. He didn't really know any of his father's friends and all his cousins were little, so he simply sat at the table wondering when he could finally go home.
"Hey." he heard a voice say. He looked up and saw Cooper sitting across from him at the table. "You bored already?" He laughed and took a sip from his glass of champagne. "Sort of. I don't have much to do here. I'm underage and the DJ hasn't even gotten here yet, so..." Blaine fidgeted with his bowtie.
"Hey there cutie!" a high pitched, female voice cried out. Cooper looked up and smiled at a blonde bridesmaid who had some kind of mixed drink in her hand. "Oh, hey!" He smiled back and motioned to the chair next to him. Blaine eyed the girl and crossed his arms. "Blaine, this is Kelly, one of my mother's co-workers." Kelly smiled, her blue eyes appearing to sparkle under the lights. "Hi, Cooper tells me you two are stepbrothers now." Blaine felt like rolling his eyes, but there was no subtle way to do it in front of the two of them. "Yeah." Blaine pouted a little. Cooper seemed to have gotten over their kiss really quickly.
Kelly and Cooper laughed and flirted all night. Robert and Leslie were at the 'main', long table, so Blaine couldn't help but sit where he was already. He felt like staying in the bathroom all night, but that would make him seem like a douche or really sick.
The DJ announced that a slow song was coming on and all the couples should 'head to the dance floor'. Blaine rolled his eyes, staring at the candle in the center of the table. He felt a brush on his neck and turned his head upwards. "You gonna dance with me?" Cooper smiled his movie star smile, making all of Blaine's previous bad feelings towards him wash away. "Wha-" Blaine furrowed his brows. Why was Cooper doing this? Was it to embarrass him? Make him happy? He really didn't care either way, he was going to dance with Cooper. He grabbed onto his hand, nodded and said "Sure."
Cooper guided him to a slightly dark, secluded corner of the room. It was still a part of the dance floor, but the lack of light made a lot of people avoid it. Cooper held out his hand, Blaine grabbing onto it and placing his other hand on Cooper's shoulder. He felt goosebumps run up his arm when Cooper lightly placed his hand on his hip. They swayed to the melody and Cooper brought Blaine closer to his chest. Blaine looked down at the fake wood floor, savoring the moment.
He felt Cooper's breath hit his ear, gripping harder onto his hand and shoulder. "You know we can't do this for much longer." Cooper whispered. Blaine almost paused in dancing, his stomach sinking. He continued, but a little bit slower and off felt Cooper's thumb brush against his hand. "We're brothers now, officially." Cooper got closer, his lips brushing against Blaine's ear. Blaine shut his eyes tight. "You're cute, but a little too young. You'll find a great guy one day, I promise." Blaine felt a sting starting in them. Cooper eased his head down and planted a small kiss on Blaine's neck. He pulled back and smiled, letting go of Blaine's hand and hip.
Cooper walked back to the table, asking Kelly to dance. Blaine stood, feet still planted in the dark looked on in anguish as the two of them stood close and laughed together. That was it. It was really over. He and Cooper would never be anymore than brothers who kissed on the lips and ate McDonalds together. He had waited too long to ask Cooper about the nature of their relationship. Now it was over. Done with. Never to be brought up again.
He excused himself to the bathroom, running once he got halfway down the hallway. He pushed open the doors, looking around to see if anyone was in there. Surprisingly, no one was. He quickly turned on one of the sinks and splashed his face with cool water, trying to get the hot tears threatening to drop to stay back. He felt his throat throbbing as sobs escaped his lips.
This was really happening. He was actually crying because his step brother, who he never had a chance with in the first place, had dumped him at their parent's wedding. Was dumped even the right word? It's not like they were in a relationship. Turned down was more like it. Turned down by someone he thought he might be in love with. He was so stupid. He had somehow convinced himself his gorgeous, amazing stepbrother would return his feelings. He was fourteen. Did he really want a twenty one year old to fool around with him? Was he that 'crazy in love'?
He sighed, looking in the mirror and wiping his face with a scratchy paper towel. It was over and he had to accept that. Cooper was now just he brother. Now just Cooper Anderson. Now just family.