It wasn't fair. The way his human emotions were playing him like a child outside a candy store, taunting and laughing at his misery. He's heard the butchered expression many times: let your heart be your compass. What good does that do for a man whose compass has always steered him away from temptation and was shattered and sown together by measly strings? Compasses were defunct. Compasses lie.

If you think you're facing North toward the Heavens, a compass will only tell you that you're facing South toward Hell, driven by the same... passion, the same insanity that once, ironically, reassured you of normality. And what use would derive from a broken compass? Compasses were useless. Compasses filled said wanderer with false pretensions.
He came to realise that the one thing holding him back was his friendship with Dean. If—and only if—he truly loved him, perhaps he wouldn't be so frightful of losing the one thing that mattered most in his life: the peace, the clarity, the things that actually made sense to him.
There was also a preconceived notion whispered across the tongues of mundanes that love gave you wings. And if this is true—which he wanted to believe so badly because he needed something real to hold onto other than blind faith—then Dean already provided him with that. Even after Castiel fell and he lost his wings literally, he sought after the hunter and found something more lying beyond him. He found every problem-from using souls for his own twisted games and casting his brethren out of Heaven-were all lost, dissipated with every other forgotten heartache.
Heartache. Angst. A soundless laugh escaped his lips. Now these were sentiments he was positive of currently experiencing.
It's ironic, and almost poetic: how a man so familiar with himself could turn into a coward, corrupted by a man who depicted himself to be the same. (Castiel would never think Dean was a coward, not then and not ever.)
Rest assured he enlisted Sam for moral advice. Sam was notably intrigued by his presence (three in the morning wasn't exactly visiting time at the Winchester's bunker) but nonetheless slung his arm lazily over his shoulders and gestured him inside. Cas waded on his question until they sat down, face to face.
"Sure, what's on your mind, Cas?"
He swallowed a thick lump in his throat. He couldn't believe what he was asking the younger Winchester. Sam was baffled as well. "So, let's see... you're experiencing new things, things you haven't told a single soul about." Cas nodded. "And you think that by... experimenting... with me... it might sort things out?"
"You're the only person I can trust, Sam. I'm sorry if this is too overwhelming. You don't have to comply with my inquest."
"What about Dean? I thought you and him were tight. And now it's like you two have to strain to look away from each other."
"You notice that?"
"Of course I notice, Cas. I'm not blind, and I care about you a lot."
Cas's lips managed a smile for the first time in a long time, then immediately faded upon answering that Dean was the object of his affection, the reason for his foreign feelings. Sam's hazel eyes widened and fell with understanding and took the initiative to lean closer, prudent to make neither of them rue the decision later.
"I can't stand to see you miserable, Cas. I want to help in any way that I can," he explained, resting a hand on his knee.
And, as sensibly as his heart was with his words, Castiel found his lips to be no different. It wasn't passionate enough to be sentimental, but was gentle, kind, and just enough that when Sam retracted it left Cas feeling a little more reassured.
"Good," Sam rejoined, removing his hand and taking a moment to search the angel's face. "So I guess that means you're-?"
Yes. He would call a scarlet face and tightening jeans major indications of rooted affection.
After Cas informs Sam that he has to see Dean, Sam doesn't do anything to impede his actions. He helps him to his feet, and before sending him away with a proper hug, asks out of the mere curiosity lingering in the corner of his mind if things will be "weird" between them. Partly because he understands Cas is confused enough as it is with his feelings and mostly because he doesn't want to do anything to deter their friendship; that despite blood, he is his brother next to Dean.
And he rambled for a good minute about other superfluous things like Sam does but that was just the gist.
Cas laughs, cupping a firm hand around his cheek, replies, "I love you, Sam," and saunters off in search of his true love.

-.-.-.-.-

Cas finds Dean that same night sitting on the edge of his mattress swabbing and reloading his guns. Most likely for the trunk arsenal judging by the range of artillery—long necks and firearms and hand grenades. He was about to emerge from behind the half-closed door when something stops him short; a pang in his chest. Behind the doorframe, and outside Dean's realm of perception, this moment was the last time things would ever be the same: Dean going about his regime, saving people and hunting things, and Cas distancing himself when things got out too of hand and returning only to provide necessary solace. And yes, surprisingly, he did like things that way. Cas never had two people he could truly call his, and two people is equivalent to a family. And that's what they were, the three of them: family.

He takes a deep breath, preparing himself for the consequences as he pushes the door aside with forceful determination. Dean nearly jumps from his seat, grabbing a hold of one of the longer guns and aims it at the looming figure. Cas throws up his hands. He really should have known better than to waltz in on a man while he's holding a weapon.

"Cas, I—uh, sorry, it's a defense mechanism," he explains, lowering the glistening object. As if his pants weren't soaked enough, he's pretty sure urine crosses off the list. "What—what are you going back? I thought you had some angel asses to fry."

I can't stop thinking about you. He gulps. "I, um—uh—" These ums and uhs were adopted into his vocabulary around the time he became human. He always found himself lost for words and they were like his caulking, something to adhere to when he wasn't sure how to go about expressing himself. He finally settles with the truth in a simplified form, that he came back for him.

This seemed to catch Dean's attention. He completely detached himself from his weapon and craned his head to look at Cas—to really look at Cas—as if this was a close encounter and Cas was the celestial being. "You… came back for me?"

Cas took the gun as the initiative of Dean trusting him and stepped in, but probably didn't make more than a few inches when he blurted "I love you."

Dean's reaction completely countered Sam's response when Cas had told him earlier that he loved him; his eyes flew open and he stared at Cas, not directly though. He stared at Cas dumbfounded, like he couldn't even comprehend such a statement, and so simple of a statement it was, too. It even made Cas feel light, like the words were once a substantial amount of weight on his shoulders and he feels at ease for the first time since… well, quite frankly, ever.

"I lo—"

No. He didn't want to hear that line reiterated like a broken record: overstressed and meaningless. He didn't wanted to hear Dean say it out of civility; he wanted to hear Dean express his feelings more dynamically, more attentively. He wanted not only to hear Dean say these words but he wanted to feel every part of Dean when he said it; he wanted Dean to hold him in his arms; he wanted him to kiss him, and not just any kiss. He wanted the heated passion from new contact, the anguish from years of yearning to be with him physically, and the anger built inside them both to drive them to claw at each other when they were making love.

He wanted it all, and moreover, wanted them to be one soul. The only thing that had been delaying him for so long was what Dean would think if he knew Cas was dreaming of all these vulgar thoughts. But looking at the hunter now made him realize something very important: if Dean truly loved him—whether it be the way Cas thought of him or just as a brother—he wouldn't mind Cas making the initial move. He knew Dean valued their friendship so much that an intimate move wouldn't possibly be the thing in the end that would tear them apart. Both men were bound to be captured by Heaven or Hell (what difference did it make, really?) sooner or later, and even then, he knew they would find their way to each other.

These are the thoughts that ultimately led to Cas kneeling down, moving his hand to the nape of his neck, and abundantly kissing him, harder and faster than he was planning on. He didn't forget to retract, however, Dean did. He wavered over his lips, smiling finding Dean's warm hands coming to rest on his back and before either of them were aware, their tongues were in a wet flesh war, vying for dominance and Dean lured him on top of him by his shirt collar, lips never once coming up for oxygen.

That was also when Dean said I love you in return and the angel was satisfied because it was said during the aforementioned things he was craving so earnestly for. And this time, it was different hearing Dean say those three words because for the first time he didn't say it in a fraternal way and because he had to, but because he said it hungrily and because he needed to. Cas was Dean's salvation and Dean was Cas's hellfire, and whether they were singing with the congregation or spawning under satanic lust—they were in love. And somehow, that was enough.