What would it be like to get his fingers to her pussy? What would he do to it? Would he know what he was doing? Would he act by instinct? Or would she show him what to do?
Later on, what would she look like completely naked? How good would her breasts look? He imagined what it would be like to slide his cock into her and how she would gasp as she felt it filling her up.
He could see himself, starting off slow and then fucking her harder and harder till at last, he came inside her.
That would be it, that would be all that he'd need...