Even if Lucas had checked with her again, Riley would have insisted it was okay. She'd decided it was okay. In a few hours they'd go home and wouldn't remember it had ever happened. Maybe one day there they could have their first time together again. She hoped that they would; she really did love him and had always intended that one day it would be with him. The end of the world was just pushing her to ask for it sooner.
Her heart pounded as his hands moved in ways he'd never touched her before and instinct told her she should stop him. She was too nervous, too unsure that she was actually ready to do it, but she was determined and she ignored the urge to run away. This was how it was supposed to be. With someone she loved and who loved her more than anything. Someone she knew was going to be gentle with her and if she really didn't want to who she knew she could stop without hurting his feelings.
She definitely was't going to stop him. She'd made the choice. She smiled, hoped it didn't look nervous, leaned into the familiarity of kissing him for a few moments before tentatively reaching to tug on his shirt.