The last chapter! Yaaaay! Please bear in mind that this is the first fan fiction I've ever written ever, so feedback is much appreciated. Disclaimer: I own nothing, etc. Thanks for reading! And putting up with my incompetence... Hehe.

The jaws of death were surprisingly pleasant. A little wet, but warm and soft. Batman moaned a little at the pleasant sensation, and the pressure increased. Suddenly his eyes snapped open and he jerked his head back. The Joker was kissing him.
"Wh-what do you think you're doing?!" Batman cried, voice closer to Bruce Wayne's than to his usual fearsome growl.
"Batsy, Batsy, Batsy. You didn't honestly think I would kill you?" His voice dropped, becoming husky. "What would I do without you? You. Complete. Me.""
He moved closer, running a finger along Batman's jaw. His only response was a violent jerk away from his hand.
"You know what your problem is, Batsy dear? You haven't learnt to expect the unexpected. It's all those rules of yours. You need to let go, stop thinking of things as being so black-and-white. The only sensible way to live in this world is without rules!"
With that he grabbed Batman by the back of the neck and violently mashed their lips together. His tongue invaded Batman's mouth, hot and wet and urgent. Batman tried his best to pull away, but the Joker had him firmly held in place. Gloved hands crept all over his suited body, trying to find a way in. He struggled violently for what felt like an age, before Batman finally realised it was useless trying to fight back his way. Sometimes violence just wasn't the answer, particularly when dealing with the Joker. It was time to introduce a little anarchy.
The Joker's tongue was still in his mouth, and this time Batman met it with his. The momentary surprise this caused allowed him the opportunity he had been waiting for, and he bit down hard on the Joker's lip. His teeth punctured skin and he tasted the salty tang of blood. The Joker staggered back, licking blood off his lips and laughing. His mad cackling reached fever pitch and he swung his fist wildly at Batman's face, almost falling over, but still managing to shatter Bruce's nose for what must have been the hundredth time since they met in the alley. Batman cried out in pain, the taste of the Joker's blood now mingling with his own.
Still laughing, the Joker grabbed him by the neck again and mashed their faces together. Batman could feel the barely contained laughter shaking Joker's body as his mouth was once again invaded. Against the blinding rage he noticed the hot breath blasting his face was surprisingly sweet. He'd expected someone like the Joker to have very poor dental hygiene, but Bruce Wayne had made love to supermodels who smelled worse. The thought brought back that uncomfortable feeling, the one which stirred his loins and made him sweat.
Normally Batman channelled his anger into his fists, beating criminals into submission. Now, the Joker was attempting to kiss him into submission. And Batman always fought back.
This fight was a battle of hot mouths and wet tongues, soft moans and nipping teeth. This wasn't what Batman had been trained for, but Bruce Wayne was. This was the chief pastime of billionaire playboys, and Bruce used that knowledge to his advantage. He couldn't fight the Joker, but he would still win.
Without his hands, Bruce's power was limited (although if he had the use of his hands he wouldn't be in this situation). However, he was still talented with his lips and tongue. Before long he had the Joker moaning, letting Bruce kiss his throat and bite gently at his earlobe.
The Joker had use of his hands, but Batman's body was encased in a seemingly impenetrable suit. Still, he ran his hands over every conceivable inch of Batman's body, rubbing and stroking and looking for a way in. It was a little difficult for him to concentrate with that hot tongue in his mouth, making his body respond in ways which Harley Quinn had never quite managed with all her beautiful sweetness. Before long he'd given up trying to get Batman out of his suit, focusing instead on bringing their bodies as close as possible together and letting the masked man have his way.
Bruce brushed his lips against the Joker's jaw, moving across to place a series of small kisses on his throat. The Joker gasped, rubbing his head against Batman's like a cat. Those lips kept kissing along his throat, pausing at his earlobe.
"Untie me." Batman breathed, biting gently on Joker's ear.
"Now now Batsy, you know I can't do that." The Joker muttered, trying not to moan in pleasure long enough to talk.
"Untie me." Those lips we tracing the line of Joker's throat, giving him goose-bumps.
"But Batsy..."
"Untie me." Batman found the Joker's mouth, kissing him infuriatingly lightly on the lips.
"Hhhmmmmppphhhhh..." The Joker tried to force those lips open, but Batman drew back.
"Untie me." His normally threatening growl was a husky whisper, promising nothing but good things should the Joker comply. His eyes, normally burning with anger, now smouldered with passion. His mouth, normally sneering or set in a grim line, was curved in a beautifully seductive smile.
"Untie me."
The Joker sighed, pulling a knife from his sleeve. He ran his hands slowly up Batman's arms, keeping their bodies close. He stared into Batman's eyes, their faces millimetres apart. The knife sliced quickly and easily through the bonds, and the masked vigilante fell to the floor. Joker laughed, throwing himself down beside his prey.
"Oh Batsy, this is going to be so much fun." He reached down to undo his belt, when he was flung suddenly across the room.
"Sorry lover boy, but I don't fuck on the first date." Batman growled, picking up the knife and slashed the bonds around his ankles before rising to his feet.
The Joker flapped his mouth open and shut, bizarrely at a loss for words. He had been so sure. He had seen the desire in Batman's eyes. How could he have been betrayed like this? How could he not have seen this coming? He was the Joker, the perfect example of everything that was wrong with human behaviour. He was the one who should never be trusted. He should be fucking Batman into the ground right now. But he wasn't. And you know what? That was pretty funny. That was goddam hilarious. God, it made him laugh.
Hysterical laughter erupted from the Joker, filling the putrid room with its manic peals. Batman looked at the madman with disgust. The Joker had gone too far this time, and in response he'd had to sink to an all new low. Batman didn't use sex as a weapon. He left that to the she-cats. And he certainly didn't enjoy it. His body may have betrayed him (and painfully too-the suit left no room for desire), but his heart and mind were still filled with hate.
So why did he feel something akin to regret looking at the cackling lunatic he'd thrown in the corner? He should be beating his senseless and handing him to the police. Instead, he was standing there, loins burning, half-wishing he was still tied up with the Joker's hands running over his body.
No! He couldn't feel that way. He didn't feel that way. He gave one last hate-filled glare to the Joker, then turned haughtily, running his eyes over the room for the way out. A large window was set in the wall behind where he had been tied up. Looking out, Batman was surprised to see it was early morning. The skies were still grey with rain, but the sun was peeking timidly over the horizon.
They were high enough for Batman to get a good view of the city. Gotham looked surprisingly beautiful, the early-morning sun reflecting off the raindrops and casting a fresh glow over the normally filthy city.
Caught up in the startling beauty of the new day, Batman had not noticed that the laughter had stopped. He did notice however, when fingers circled his wrist, pulling him violently around. The Joker's manic face was inches from his, dark eyes staring up from black holes, sweet breath coming from a red grin. But the Joker wasn't smiling; beneath the scars, his look was pleading.
"Stay." His voice was small, lacking the high lilt that normally characterised his tone.
For once, he didn't sound insane; just small and alone. Batman felt a sudden twinge of incomprehensible pity for this man; eaten away by insanity, the Joker was a man forced by his own nature to do evil deeds. His madness had pushed him into a corner of his own life, only leaving him enough room for chaos. He would never know love or kindness, because he by nature shunned the positive sides of humanity. Batman did not pity him his life, but rather his lack of it.
And yet, they must be enemies. That was their destiny. They would fight each other until it killed one or both of them. That was the synergy of their relationship; good and evil, light and dark, crazy and sane.
Batman released himself gently from Joker's grip. The Joker let his hand fall to his side, where he curled it into a fist. Not an aggressive fist, but a gesture of frustrated resignation.
"You know I can't stay." Batman growled. "If I stay, I have to take you in."
"I know, Batsy. " Joker smiled ruefully, licking his lips.
"Joker?"
"Mm?"
"Don't call me that."
Batman swung round, running full pelt at the window. Smashing through the glass, he spread his cape wide and glided into the morning. A bat returning to his cave after being caught out too late. A vigilante returning to his hideout before the police found him. A playboy returning to bed after a big night.
The Joker leaned against the frame of the broken window, watching Batman glide to the next building and drop out of sight. He giggled a little, running his hand through his greasy hair. A silver knife twirled between his fingers, flashing in the morning sun. Suddenly he dove a hand into his pocket, pulling out a sleek black mobile phone. He pressed a few buttons, then held the device to his ear.
"Whaddya want?" A voice grunted on the other end.
"Larry?" The Joker barked.
"Y-yes Boss?" The voice changed from a grunt to a fearful whine.
"We need a new plan."
He slammed the phone shut, face splitting into a huge grin. A bubble of laughter welled up inside him, bursting forth in an ear-piercing cackle. He spread his arms wide, greeting his beautiful city.
His lip stung where the Bat had bit him, blood still leaking from the wound. His body burned with a new set of emotions, new desires which his Batsy had awoken. He knew what he wanted now, and for once it wasn't chaos or destruction or stolen goods.
Batman may have escaped, but this wasn't the end. One day, the Joker would bring him over, send Batsy as mad as he was. And then he, the Joker, the Clown Prince of Crime, would have the last laugh.