Well, not necessarily. He would have been fine with just snogging Aileen, which he had also yet to do. They didn't necessarily have to get sans-pants. Although, unsurprisingly Will wouldn't complain if she offered.
Any ways, Will couldn't really think of any other thing he could use as reason for a reward, so it was time to get away from that. "Just tell me what you want me to do," he said with a bit of a grin, raising a hand to brush some of her hair out of her face.