It would probably be worse for you to back down...

You hesitate for a few awkward moments. You don't like where this is headed, but you can't see yourself turning down a direct challenge like that without compromising your standing. You begrudgingly sit down on the edge of the bed, and conjure up some false bravado to disguise your unease:

"Sure. Fine by me. Are we going to get this over with, or what?"

There's a flash of malicious glee in the imp's eyes, before he flutters to the floor and walks forward to where you are seated, all business all of a sudden.

"Did you really just say that you want to 'get this over with'? My, but you're an eager mortal." He pushes your knees apart with his clawed hands, and before you're able to protest, he imposes his own body between your legs to keep them from closing. "I thought I had detected a hint of envy, but maybe I was just being a bit too harsh..." He slowly unzips your fly for you - given your own apparent reticence to take the initiative, lest you seem too cooperative in this situation - and with unnerving efficiency whips your trousers right off, and tosses them into a far corner of the room, before using one hand to push you back into a lying position, so that he can prop one hoof up on the bed frame and push up against you at a better angle.

You're increasingly finding yourself in a more and more compromised position, as the imp dispassionately and methodically ignites your underpants in cold fire with a flick of his finger, the garments immolating and vanishing in an instant, leaving your balls and stiffening rod on show.

"Maybe 'envy' wasn't the right word... A starving man doesn't envy the king's dinner plate, even though only his eyes get to feast as his stomach merely growls, wouldn't you agree?"

You wouldn't agree. You would resoundingly disagree, were it not for the imp hefting his crimson cock into view and allowing it to slap down lewdly atop your own, inflicting a firm, fleshy impact, and persistent, warming pressure upon your balls and shaft. You affix your eyes to it, analysing the size, and find that it just matches yours. Despite yourself, you exhale a sigh of relief...

... Which becomes a sharp, shaky inhalation, as the imp leans forward, sliding his own length against yours, aided by a few errant droplets of lubricating precum, which (you would be ashamed to admit) are not only his. You look up at him, confused, and are met with an obscene expression of enjoyment at your expense, his forked tongue lolling out lewdly as he breathes steadily and combs up and down your body with his dark, slitted pupils. When he sees you looking up at him in alarm, he tilts his head and pouts, then rolls his hips a bit harder, smiling. You see his game- he's just messing with you, trying to make you feel small, and...

... Wait... Wasn't he, y'know... Shorter a minute ago?

Your eyes widen slightly as you take in this new information. Yes, the imp is definitely several inches taller than he was when this began. You can see more of the matted fur of his legs now, each time he rubs up against you - and he isn't even using the bed frame as a boost any more! Both hooves are planted firmly on the ground... And doesn't the room seem a bit... Bigger than before?

"Hey, mortal. Don't get distracted." You meet the imp's arrogant expression and, in acknowledgement, he pushes down a little harder against your length. Damnit... Damnit! Why does it have to make you feel this good? "I know you're just burnin' for me to rub my warm meat all over you, but we're not doing this just for fun. Are you ready to concede?"

Your heart lurches, and you look back down at your paired members... Getting acquainted. Despite what he says, the contest is a close one; but he has the assistance of gravity, and when your rigidity ebbs just for a moment in the face of his onslaught, your member is weighed down by his own, squashed into your navel. The pressure persists as he luridly slides his cock back and forth along the length of your member, seeming to edge a little further forward than yours reaches each time... Until finally, your prick is hidden completely from view, and with a sinking feeling, you see and feel his bulbous, leaking cock-head rubbing triumphantly against your belly, smearing a patch of sticky, smoky-smelling precum across your bare skin.

This can't be happening, you remind yourself. This can't have happened! You thought they were almost perfect matches for size! So how is it that now your admittedly-flagging erection seems so much... Smaller and softer than his?!

The imp grasps his hot, crimson python in one hand, and lifts it away, finally allowing you to take in the extent of your predicament. Everything your manhood lost during this game; in length, girth, and straight-forward rigidity; has been gained by his own. Your cock and balls are as modestly-proportioned and... Cute... As you can ever remember them being, while his balls look like they're straining with virility, and his monster-cock is barely less than absurd, even given his anomalous increase in height.

You hold your breath as you look, first at his engorged demonic schlong, and then at your own parts. And then back at his schlong, for longer this time. You fight back the urge to sob, but can't avoid your eyes watering, at least a little. How did it go so wrong, so fast?

"Mmm. Guess that settles that quandary." The imp rests his cock against your taint as he picks at his teeth with his free hand, and you squirm a little at the warmth of it, quashing a sudden, inexplicable urge to push your thighs together, squeezing yourself around it, and then... "Sucks for you that we came to the mutual agreement that a cock-measuring contest, of all things, was how we were going to set the tone for the rest of our time together..."

Evidently seeing just how badly his words are tearing you up inside, he winks reassuringly and blows you a kiss. "Don't worry baby, I've still got what you need... And then some." You squeal as he pinches your prick between his middle and index finger. "Size isn't everything, after all."