Based on Season 2, Episode 15 "Tall Tales"
The moment Dean burst into that theatre he knew it was a trick, and he cursed that said Trickster for being able to see through him.
For on the stage was a large red velvet bed, he had to give the boy points for taste, but it was what was on the bed that was turning Dean's mouth dry.
Or rather, who was on the bed.
Sam was kneeling up on the mattress waiting for Dean, his nakedness just modestly covered with a single silk sheet. He threw his puppy dog eyes in Dean's direction, and it was all the older hunter could do to stay on his feet.
Dean licked his lips, which had gone ridiculously dry, and ran a hand through his hair.
"It's a trick, it's a trick," And he knew it was just a trick because the real Sam was following the plan and waiting outside the building, ready to burst in at any moment.
Plus Sam had only ever stripped for Dean thus far in Dean's imagination.
Damn this trickster was good.
"Does it matter if I'm only a trick Dean?" Sam asked, brushing his hair out of his eyes with one hand and trailing his bare chest with the other.
Dean held on to the nearest seat for support.
"You're not real," Dean hung onto logic; a difficult feat in his current – ahem – condition.
"It'll feel real Dean. More real than anything you've ever dreamt up." As he spoke, Sam made his way off the bed and started to move towards Dean.
Dean looked up for a millisecond then quickly spun round to face the rear wall.
"Dammit Sammy, put some clothes on!"
"And where would be the fun in that?" Sam asked, "I thought you wanted to look – haven't you always wanted to look, Dean?" And he wrapped his hands around Dean's waist, his face lost in Dean's neck as he began to trail kisses across the skin there.
"Oh sweet mother of-" Began Dean, but was cut off when his 'brother' grabbed his crotch and started palming him through the fabric. Despite himself, Dean leant back and in doing so could feel Sam's erection pressing hard against his lower back.
Sam used his height to his advantage and, tipping Dean's head back further, snaked his tongue into his big brother's mouth.
There was a movement in the theatre and Dean jerked forward and away from Sam's mouth.
"This isn't what it looks like!" Dean screamed at the seats, amazed his voice could stay steady.
"Please, don't stop on my account," the Trickster said, moving into the light and settling down in one of the rows to chew on a candy bar.
"Is this your sick idea of a joke?" Dean asked, trying to untangle himself from his brother with little avail.
"Actually, think of it more as a gift – I rub your back, or more accurately Sam does, and you rub mine. Let me off Scott free, and I will leave him here as long as you like."
Dean hated to admit it, but the Trickster's offer was tempting. The stake against his chest reminded him otherwise. He swatted away Sam's hands which were starting to undo Dean's belt.
"But you'll keep causing mayhem? People will die?"
"Accidents are inevitable," the Trickster replied with a shrug, unwrapping another candy.
"Then I can't let that happen," Dean responded with resolve, not allowing himself to turn around and look at the one thing that he knew could change his mind.
"Then I'm afraid Sam was right Dean, you really shouldn't have come alone."
"He didn't." The real Sam stepped through the theatre doors, Bobby mirroring him, stake in hand.
Dean spun round, the blush on his cheeks already spreading as far down as his neck, but where the doppelganger of Sammy had been, stood two scantily clad girls. Admittedly ones who looked like they wrestled for a living.
He turned back, wondering if maybe he had dreamt the other thing, but giving up when the Trickster winked at him.
What followed was a close shave, and Dean almost felt bad about ganking the bugger – when he really could have come in so very useful. But as always the job came first; Sammy came first, and if the Trickster had had the chance to tell him how Dean felt...well it just didn't bear thinking about.
As they reached the Impala, Sam stopped before getting in and looked at his brother –
"Dean, what happened before we got there?"
"Oh you know," Dean responded, dismissively, "Just up to his usual tricks."
"It's funny, I could have sworn I saw – oh never mind."
Dean avoided his eyes.
"Hey Sammy?"
"Yeah."
"I'm um, you know..."
"Me too," said Sam, certain his brother was just saying sorry for his behaviour the last few days. Dean was just about to say something else however, when Bobby stuck his head back out the car.
"You boys are breaking my heart, can we just go?"
But the way Bobby avoided looking at Dean made Sam sure that what he had seen in there had not just been his imagination.