The offer

“See, this is the deal,” Luna said, getting off the bed and standing behind him. “you’re going to fuck all three of us today Harry, and you will do so without stopping. Once you start, you don’t get to rest.”
“Also,” Ginny added, “you will fuck each of us for 30 seconds exactly, after which you’ll move on to the next girl. That way, we all get to enjoy you.”
Harry’s eyes widened, and he got a huge grin, not in the least hampered by Luna’s small hand, which had slid down his chest and was unbuttoning his pants.
“Lastly,” Hermione continued, “once you start cumming, you will stay inside the girl until you finish every last drop inside. You’re not to pull out until you’re completely drained.”
“Okay then, let me get a condom,” Harry smiled.
“Oh no you don’t, I want to feel all of you tonight Harry,” Hermione shook her head.
“But… are any of you using the protection?” Harry looked over the three of them. Luna had managed to get his pants off and was running her hand over the bulge in his underwear.