Disclaimer: Gossip Girl isn't mine.

AN: A new one-shot after finishing I Do. I've started this quite a while ago but for some reason couldn't finish it. But here it is. I hope you all like it. Click the purple button and review. Let me know what you think- the good, the bad, the ugly.

Regret

Nate stared as she walked across the courtyard toward their group with an extra bounce in her step. He couldn't help but stare at her. Who wouldn't? She may be petite but she exuded an aura that made heads turn. It didn't hurt that she was gorgeous with her curly hair, clear skin, and doe eyes.

Sighing inwardly, he thought about how much he missed her. He missed her calling or texting him to remind him about things–which used to annoy the hell out of him, he missed her special smile that she used to give him, and he missed having her in his arms.

Now, as far as he knew, she didn't call nor text her new boyfriend as often she did Nate. He wasn't surprised, after all, he was the one who used to remind him about important dates and/or tell him what to get for her during special occasions.

Her special smile, it was now bestowed on someone else, and it had that extra sparkle in her eyes that was lacking before. In his best friend's arms was where she found solace and happiness. He could see how protective he was of her and how much he cared for her.

Nate finally got the girl. She was every guy's fantasy and she was the girl of his dreams. Dan had broken up with Serena when he realized that he was in love with Vanessa. She was hurt and she needed somebody to comfort her, and he found the perfect opportunity, making sure that he was always there for her.

He and Blair broke up, earning her wrath. He and Serena weren't left unscarred after Blair had exacted her revenge. But pre-boarding school Serena was here and she fought back. The war only ended when they all finally decided to talk and settle the issue like adults, which was highly unusual. Everyone thought that it was easier to get along.

Their parents were surprised when they heard about the news. Lily was concerned but supportive. Blair was her daughter's best friend and she was worried about their friendship. But she knew that Blair and Serena's bond was strong and would overcome this. His parents were definitely worried since they did business with Eleanor Waldorf. Not only that but because his mother had always liked Blair and was hoping that they would get married one day. She had actually asked him if this is what he really wanted; if Serena was who he really wanted. His answer was a resounding yes.

He loved Serena. He will always love her. He had been struck by her beauty when her first met her, with her long blond curls and blue eyes. He had loved her outgoing and daring personality. She was vibrant, full of life, and laid back. She loved to drink and go to parties, and sometimes came home early in the morning drunk. Flirting was also something she did quite frequently. He didn't blame her; she was gorgeous and sexy and guys just swarmed all over her. He just tried to understand that she was simply being Serena, the girl he would give up almost anything and everything for.

His ex-girlfriend, Blair, on the other hand was more serious. She planned everything down to the minute details and she could be vicious when she didn't get her way. But Blair could also be sweet and thoughtful. He remembered when she gave him a scrapbook full or their pictures and mementos for their anniversary. He still kept it in his special Blair box, wanting to cherish the memories.

Nate felt his heart clench as he watched Blair greet Chuck with a soft lingering kiss, and wished that he was the one she was giving it to. He couldn't help but look away when Chuck licked his lips, making her giggle and giving him another quick peck.

When he learned about them through Gossip Girl, he couldn't hide his disbelief. He couldn't wrap his mind around the idea of them together. The entire day he was in a daze trying to understand how it happened. Back and forth, Chuck and Blair, Blair and Chuck. His best friend and his ex-girlfriend.

He worried about Blair. Chuck may be his best friend but he knew how he treated women. Once used, he just threw them like yesterday's trash. He didn't have any problem airing his concern to Chuck and he visited him at the Palace that night.

"Look man, I care a lot about Blair. If you're just going to play –"

Chuck cut him off. "I'm not. I'm going to treat her better than you ever did."

Nate felt as though somebody punched him in the face. "Just don't hurt her," he said and turned to leave.

He wasn't satisfied and felt the need to warn Blair. But she just scoffed at him, telling him he was being a hypocrite. "Leave me alone, Nate. You lost your chance to be concerned about me when you broke my heart. You did it not only once…but a lot of times. And it was Chuck who was always there for me. He makes me happy, Nate. He makes me feel beautiful, wanted. And for the first time, I don't feel the need to be so damn perfect all the time!" By the time she finished, she was almost shouting.

That was a few months ago and now they were slowly going back to being friends again. Lately, he noticed that Blair smiled more often. It wasn't the polite smile that was dictated by UES society, or the cynical smile she used to give people she didn't like, but a genuine and giddy smile. And her laughter, like a melody, followed him everywhere haunting him, taunting him.

Blair was now more comfortable with her sexuality. He'll never forget that morning when Chuck's limo pulled into the curb in front of their school. They got off the vehicle and it was difficult not to notice that her hair was less than perfect and Chuck's clothes were slightly rumpled, not to mention the glow in her skin and the satisfied smiles they both sported the entire day. It made him want to puke. That night, he dragged Serena to his room, frantically kissing and caressing her, and almost ripping her clothes off in haste. He almost willed her to have chocolate brown hair, a smaller waist, and shorter legs.

Serena didn't have problems in showing affection. Sometimes, she would go up to him and give him a long and thorough kiss in front of everyone, which he admitted, made him shy and embarrassed. Of course he would kiss her back. But once, in the middle of their PDA, Blair popped in his head and thought to himself that she would never do anything like this.

Although Chuck and Blair might be more subtle, Nate always noticed. When they thought that no one was looking they would sneak light kisses and share a hug, and they always seem to be touching each other in some way— when Chuck would place his hand on her lower back or when Blair would hold on to his arm when they stood together. He was sure that if he looked under the table at that moment, they would be holding hands.

He must be a masochist because he purposely dropped his book on the floor. Ducking his head, he took a peek and a lump formed in his throat. Their hands were clasped together and Chuck's thumb was making small circles on her wrist.

When he moved back up, without thinking he grabbed Serena's hand in his and intertwined their fingers. Somehow it didn't feel right. Her hand was soft but it wasn't small and dainty. She looked at him, eyebrows slightly raised but he just gave her a strained smile.

Mentally shaking his head, he looked longingly across the table at the happy couple. He was back to where he was before. Being with Serena wasn't what he thought it would be.

Once again, there he was holding his girlfriend, pretending, while pining after his girlfriend's best friend.

Regret never tasted this bitter.