Maybe she was giving him too many instructions at once, but he'd wanted to learn. And trying to guide him while he was knuckles deep in her... well, it was kind of hard to concentrate, if she was being honest. But he was catching on quickly- he was a good student, it seemed.
She rode his fingers as he moved them inside of her, letting him set whatever pace he felt comfortable with. She wasn't trying to overwork him or anything, she just wanted him to know where to touch her, how to help work her open enough that he'd actually be able to get that monster of a cock inside of her small body.
He added a third finger and the way he stretched her as he did was, at first, a little painful... then she adjusted and the pleasure flooded back in, even more so as he picked up the pace and her moans and whimpers grew more eager. He could probably get her to finish like this, honestly. But that wasn't what she wanted. Not yet, anyway.
So though she let him continue for a short bit longer, she eventually had to grab at his wrist to stop him, muttering a soft "Okay, okay... wait... I don't wanna come yet...". It had felt so nice, she'd been tempted to let him carry on. It'd feel much better to have his cock inside of her, though, she knew.
"You're a quick learner," She told him, pleased with how well he was doing for someone with so little experience. "I think we can move on to the main act, now. If you're ready," She was fairly certain she was. As ready as she could be, anyway. So she seated herself on the edge of his bed.
"I want to make sure we're in a position that's comfortable for you," Cass said. Missionary would probably be best. Or she could lay down right here and he could stand, her legs draped loosely around his waist, as he slowly buried his massive cock inside of her. But if he was eager to try something else, she'd be open to it. She quite liked being manhandled a bit, moved around however her partner saw fit. "How do you want me?" She asked, reaching out to slowly stroke his hard cock as she spoke. "Tell me what you want to try and we can try it."