Pearlina Headcanon: While working on Finalfest, Marina wrote a love letter and gave it to Pearl. She didn't say what it was, just that she wanted Pearl to read it. Pearl was really busy with her own prep at that time, so she said she'd check it out later.
She forgot about the letter until Marina asked what she thought of it. Not wanting to disappoint Marina, she claimed she read it and it was great. Because Pearl kept trying to avoid referencing the contents of a letter she never read, Marina thought Pearl was trying to subtly turn her down.
This was part of why Marina was so worried about Finalfest, because she thought between this and Pearl wanting to try new things, that Pearl was going to leave Off the Hook when this was over.
After the results were announced, and after Pearl literally told Marina she loved her on live television (check the dialogue she actually does lol), they have a conversation where Marina asks more directly about the letter, and Pearl confesses she forgot to read it. Apologies, hugs, and probably kisses ensue. They become a couple within 24 hours of Finalfest.