Because Vermilion Lies called me out, I'll post mine. Warning: I am an angst whore, therefore many are super angsty.

Gossamer strands connected the two, thin tendrils that somehow could never be broken.

Alone
Forget investigating Light, the handcuffs were there to make sure L was never alone.

Silence
Relieved to be free of L and the handcuffs, Light lay down to sleep and found he could not, for the tell tale clacking of keys was missing in the silence.

Poison
Touching the Death Note again, Light's memories spread like poison through his heart, hardening it against L.

Alien
L was certainly an alien who had no need for sleep, but Light knew his weakness: his dependency on sugar.

Cards
L and Light cared not what the cards held for them, as long as they held each other in their arms.

Brother
Light was glad he didn't have a brother for Ryuzaki to also watch in the shower.

Partnership
The clicking of the handcuffs locking signified the beginning to their partnership, in more than one way.

Maniacal
If L's strange personality quirks could be forgiven, then Light's maniacal tenancies could be too.

Fake
Even after gaining back his memories, there was no need for Light to fake it, he still loved L.

Rose
Ryuzaki smiled, "You want to know my name? What's in a name? That which we'd call a rose by any other word would smell as sweet!"

Identify
For L, identifying Kira and getting evidence was the easy part; breaking his heart was not.

Trash
After finding L rooting through his trash, L demanded an explanation; however it was really hard to take L's "how to catch Kira" theory seriously when he had a banana peel on his head.

Dictionary
It seemed mercy was not in L's dictionary.

Destiny
Light believed it was his destiny to recreate the world and emerge as a god with L by his side; L didn't believe in destiny.

Star
Squeezing his eyes shut, L wished upon a star he was wrong about Light.

Epic
When the epic battle between Kira and L was won, Light cried.

Shining
Looking up at Light, L's eyes filled with tears and shined as he fell to the floor.

Grease
While L scraped grease off dishes; Light put bleach in his tea.

Brainless
Why Light still let that brainless Misa kiss him, L would never know, but he did know how much it hurt to watch.

Dirt
Finally, Kira lay dying, on a dirty warehouse floor.

Monkey
Near the end, L clung to Light like a monkey, but at the end, he had to let go.

Blue
Light wouldn't- no, couldn't believe L was dead until his lips turned blue.

Ocean
Light looked at L in his casket as if from across an ocean; L was blurry and Light's face was wet.

Leaf

L shook like a leaf when he was cold; therefore, Light told himself it was more to stop the distraction than to touch the detective that he slept with L in his arms.

Serenity

While they were thinking, their faces contorted in concentration, only when L and Light were sleeping did either of their faces portray serenity.

(Lady) Luck
Lady Luck either hates L or loves him; to give L his one true love is amazing, but to take him away would be devastating.

Hearts

After sex, with their sticky skin and exhausted limbs pressed together, their hearts beat as one.

Tongue (rather than say something about L's talented tongue)

Matsuda bit his tongue when he was thinking; he spent much time biting his tongue about why L and Light disappeared frequently during the day.

Vermilion

Vermilion blood spilled onto Light's pristine shirt; his wrists bleeding freely and arms held high as he went to join L.

Deceived

After convincing L to come to bed, L burst out "You deceived me Light-kun! You told me there was going to be cake!"

Porcelain

His porcelain face was stained by the slow dripping of blood from his arm onto it; Light Yagami was left to rot in the warehouse.

Ooze

Light cared not that L's doughnuts oozed cream; he cared where L's doughnuts oozed cream, especially if it was on Light's shirt.

Serendipity

L marveled at his luck, the one time he was ever wrong about a suspect, was the one time he fell in love with a suspect; it was truly serendipitous.

Valor

Valor was never a word used to describe L, he hid and did his work from behind a computer screen… until the Kira Case.

Lampshade

When L threw Light's pants and knocked over the lampshade, broken glass splayed all over their floor; the next morning, L apologized to Watari, citing that chess is a very violent game and can get out of hand sometimes.

Hour

What was meant to take a few minutes turned into an hour; Light and L returned very late from their "bathroom break".

Photogenic

Secrecy is one reason, but the real reason there are no photographs of L is that he is absolutely not photogenic.

Dream

When L bought the handcuffs, he never dreamed he'd have a practical use for them, that's why, when it was time to release Light, he jumped on the idea.

Digital

The digitally masked voice began his downfall, "What you are doing… is evil!"

Ring

L never wore rings; he'd probably end up eating them if he did.

Wings

Light would trade half his life for wings, but in reality, he forfeited them by using the death note.

Cold

L liked to flush the toilet when Light was in the shower, just to hear him scream.

Red

Light's eyes flashed red, "I would never hurt you Ryuzaki, I love you."

Music

As Tchaikovsky's 1812 Overture filled the room, L felt the need to grab Light and dance.

Silk

Light may be angry this morning that his silk shirt is ripped, but he wasn't complaining when L ripped it off him last night.

Cover

Under the cover of darkness, Light could say the words, "L, I love you."

Drink

Drinking in the milky undertones of L's skin, Light savored their last night together, he loved L, but the world needed him dead.