Paper Hearts Background Information:

Oliver and Kara met through high school and became official in their freshman year of college until Oliver's mother found out about their relationship and figured that she only wanted her son because of them being rich. Moira accepted the relationship and did everything in her power to make Oliver Queen leave Kara and date someone like Laurel Lance or Sara Lance.

Oliver agreed to his mother's terms and broke everything off with Kara and began seeing Laurel; Kara left Starling City and lost contact with everyone, including Oliver's little sister, Thea Queen. Thea always resented her mother and brother after Kara left Starling.

Five Years Later, Oliver wanted to have a get-together for the holidays and invited all of his friends who were close to him through college. He and Laurel have been dating for a long time, and she's been dropping him off a marriage proposal, but Oliver wasn't ready for that type of commitment since the last relationship he had made him stop believing in that type of thing.

Barry mentioned to Oliver that he met a girl because of his foster sister, and he agreed for Barry to bring his girlfriend to meet their friends. All knew about Barry's girlfriend was that she got into being a reporter along with his foster sister until she wanted to be a police officer to help protect Central City. When Barry came along to Starling everyone was wondering where his girlfriend was until she walked in.

Barry introduced his new girlfriend and Kara Danvers walked in and caused the whole room to go into silence. Everyone knew who Kara was and they were shocked that she came back with a different man. They all later found out that Kara and Barry were getting married; he proposed just minutes before they arrived at the party.

Oliver was stunned that his ex-girlfriend was getting married to his best friend who was like a brother to him. It made him think about all of the years he had with Kara, and he felt heartbroken that someone else was marrying the woman he loved, or he still loved.

Thea was devastated by hearing about Barry and Kara's engagement announcement and wondered how she was gonna plan to get her and Oliver back together again. She loved how Laurel had made Oliver happy, but she missed how Kara used to make her brother laugh and smile all the time. She made a plan to get her brother and Kara together again, she just needed ideas for them to realize that they love each other still.

Things become awkward when Kara and Oliver approach each other after all those years of not seeing each other. Laurel felt jealous when she saw the way that Oliver was staring at Kara with love his in eyes. She wondered between their relationship all those years, why he hadn't made those heart eyes with her when they first met.

Kara made sure not to be alone around Oliver because she hadn't forgotten all those years with him and how he made her feel loved. She loves Barry, but Oliver was the first man she ever fell in love with and now she's getting married to someone else.

Now, all the unforgettable moments that were shared between Kara and Oliver came back to haunt them as his ex-girlfriend was getting married to his best friend.