"Mmm, good," Bastian muttered. His free hand stayed on their cocks, keeping them together. He started slow at first. His hips pulled back and moved forward with cautious, deliberate movement.
His eyes watched Harry's face. His own mouth hung open with silent pleasure. He'd done this before, with boys that were uncomfortable with the idea of penetration or when there wasn't a good source of lubrication around or when he was too lazy to do proper preparation. In some ways he preferred his this to going 'all the way'. He missed the warm tightness of muscles swallowing his cock, but there was something so erotic about rubbing his genitalia against another person's.
What they were doing was made all the more intense because it was Harry under him, squirming and groaning. He kissed Harry again but pulled away so that he could watch Harry's face as his hips pressed their cocks together again.