"Oh-" Stiles remembered now. Derek was going to ride him. And then he was going to knot him. And now he could pretend he was knotting Derek, keeping his come in his body.
"Mm, before we leave?" Stiles asked, watching Derek as his mate crawled between his legs. "That's a brilliant idea. Then I'm going to be less likely to beg for your knot whilst we're trying to-" he started, before Derek's tongue cut him off as it licked at the fingers that were still moving in and out of him.
He obediently opened his legs wider, letting Derek have access to all of him.
"Oh fuck," Stiles moaned. "Yeah. Yeah, I want that, please. Please. I want you riding me-" he rambled. "Plug'll keep me nice and open and I'll- I'll be so ready when we get back. I'll be so wet, so ready for you to be inside me-"
He arched into the drag of Derek's tongue, his dick leaking against his belly.
"I hope you brought lube. I want to fuck you. A lot. I hope you brought a lot of lube," Stiles panted. "Your tongue is going to kill me, Der-" he added, scissoring his fingers inside himself, opening himself up as wide as he could. "Look how wet you've made me- sit back, I want you to watch me put this inside me."
Stiles' free hand reached for his plug, guiding the tapered end between his legs. "Watch. Imagine what it's going to feel like around your knot," he breathed, pumping the thinner end of the plug into him, stretching himself gradually until he reached the thicker bulb. Stiles spread his legs wider, arching off of the bed as he pressed it inside him, biting on his lip and holding back a moan as the bulb worked it's way in.
His cock twitched against his stomach, imagining Derek there in a few hours, on top of him, moving against him, pushing his knot into Stiles' willing, waiting body. He uttered a little cry when it finally slid all the way in, groaning at the realisation that the tip would be resting so teasingly close to his prostate.
"Oh God," Stiles purred. "I can't wait until this is you. Is it good? Do I look good for you?"