After the war, Percy finally decided to propose to Annabeth, but he wanted to make it memorable and special, not cheesy. He asked Jason for help and he told him to propose in the lake.
The next day, Percy invited Annabeth to a picnic by the lake. He told her to bring her swimsuit. They went into the lake, Percy putting a bubble of air around them so she could breath. He took a deep breath and whispered
"Annabeth Chase, will you marry me?" A giant rainstorm started, signaling Athena's disapproval. Annabeth answered with a kiss, leading to a passionate make out session underwater.
"And please tell you're mother not to kill me." He said between kisses. She smiled, answering "I'll make sure of it, Seaweed Brain."