The offer

Before he knew it, a “Bing!” meant the timer spell went off, and Luna pushed him off her. “Go to Hermione!” she commanded.
Harry pulled out of Luna with a quick move, and his hard cock found a new home inside Hermione’s warm cunt. As he felt her tunnel close around him, he waited until he reached in her, then began pounding her hard. Hermione’s face took on a blissful expression as she humped him back, and again Harry felt his orgasm approach. Just as he was beginning to enjoy himself again, the timer went off and it was Ginny’s turn.

Afraid of cumming inside her, Harry only penetrated her with the head of his cock, but Hermione noticed: “Hey! Fuck her properly!” So he did, sliding in her. Ginny felt exactly as tight as she had when they had broken it off, and he wondered if she had had any other sexual partners. He easily found a rhythm again, and despite his worries, he couldn’t deny fucking Ginny was worth the risk. “Bing!” the timer went off, and it was Luna’s turn again.
This second time, Luna’s body accepted him even easier, and Harry was rutting deep inside her from the start. Luna’s mouth seemed to be stuck in a permanent “o” position as she moved back against him, and he felt his arousal climb higher and higher… then the timer went off again.
Hermione smiled and winked at him as he savaged her tunnel, and Harry tried to f***e his orgasm to come, but the charm went off too soon.
Ginny was happy to receive him back and humped her hips up to meet his thrusts. With how eager she was Harry wondered if she had had no other since him, for it felt like she was made to fit around his cock. “Bing!”