Cosmo remembers the set-up. He remembers the way Lina treated Don when he was a stuntman, the way she only acknowledged his existence when it was absolutely required for the picture they were shooting, and the way he and Don would laugh it off after over a drink, still in awe of how this whole Hollywood unreality worked. And he remembers the first time Lina looked at Don, not only as an equal, but as a man; he remembers the tense feeling in his stomach and chest, and then the warm, melting feelings of amusement and relief, the latter such a deep and familiar sensation by then he barely registered it, when Don threw back at Lina her own snide attitude.

And they had laughed at it that night, over a celebratory drink. Don was going to be in a picture, not just as a stuntman, but as a star. He was making their dream come true. And Cosmo was more than happy to sit at the piano and let Don take the wheel for the both of them. He distinctly remembers the gleam in Don's eye as they toasted his first picture that night, a shine that had nothing to do with the alcohol they'd imbibed. In retrospect, he should have seen it as a sign of things to come.

Even though he knew it was a sham, even though he was there to listen to every one of Don's constant rants about Lina and her high-maintenance glamour lifestyle, and even though he could tell when his best friend was acting under the flashing lights, he never thought anything could ever hurt him more some nights when he saw them together. Don's hand on the small of her back, her clinging to his arm like she needed him to keep him on her feet. Hollywood is all a show, all a sham, all a big smoke 'n' mirrors, razzle dazzle fake, he'd remind himself, over and over again. Lina's hand in his meant nothing. His arm around her meant nothing.

He would grasp hold of these truths and try to keep his head, even as he watched Don become Hollywood's biggest star. Sure, Don still thought Lina was a prissy diva. Sure, they still laughed at it together. Sure. But he saw the way Don played the crowds at the premieres. He saw that gleam in his eye. He knew, an epiphany he'd reached somewhere in the middle of their new, break-neck adventure, that he was never destined for what Don was always going to be: a true star. They'd been in it together. But it was Don's dream. And he slid right into place, complete with the blonde starlet on his arm. Cosmo was just along for the ride.

Looking back, he remembers the times just before as the best times of his life. He was a musician, Don was a stuntman, they were finally doing it, finally getting somewhere after years of sharing cheap rooms and getting laughed and booed off stages and slipping apples and crackers into their pockets at stores when they went to buy food for one meal that would need to last them the week. And there were women then, of course. Don's looks transcended his starving artist status. But those women didn't matter. They came and went. Don forgot most of their names. There was a sort of easy security Cosmo felt, even if it didn't quite stop the waves of relief when the girls left.

And very, very rarely, there were moments. The night they were sitting at the train station, after the last train had pulled out, decided their next step, and Don just ended up laughing when they couldn't agree, grabbed the back of Cosmo's neck, and said, 'It's going to be this way forever, Cosmo. Just you and me, bumming around, chasing a dream that'll never happen.' The night a pair of blonde twins simultaneously threw their drinks in the boys' faces, and they ended up leaving the bar, going back to their tiny room, and laughing about it all night.

The time Cosmo had to practically drag Don up the stairs to a different room, yank off his shoes, and start to put him to bed, before Don unexpectedly grabbed the front of Cosmo's waistcoat, and pulled him into his lips, muttering something in between kisses about 'always' and 'there for me'.

Cosmo thought nothing could hurt more than seeing Don with Lina. The other women came and went. Lina was this horrible, twisted constant, an Alice Through the Looking Glass version of star-crossed love. And no matter how much Don complained about her, no matter how much Cosmo told himself that it was all just Hollywood, all just an act, he still couldn't take seeing Don's hand on her back, her arm through his arm, couldn't take Don's acted little insinuations to the press and the fan magazines, because sex sells, and so does romance. The doubt and the jealousy, both so insidious, both so subtle, always found a way to creep in and eat at him from the inside. So he made his outward demeanour a shield built of corny jokes and slapstick comedy. It was already such a part of who he was, no one would ever notice if he was just a little too cheerful, just a little too happy. Not even Don.

And then one day, out of nowhere, there was Kathy.

Kathy, who blew a hole right through Don's ego and film star facade, and reminded him of who he really was. Kathy, who planted herself so firmly in Don's head that he couldn't shake her for anything, that he was constantly looking for her, constantly wondering where she and what she was doing. Kathy, with the ridiculous laugh and that personality that blew so hot and cold, so whimsical and then so no-nonsense in the same breath. Don and Cosmo had shared everything since they were four years old. Why shouldn't they share the same love for Kathy as well?

The more he saw Kathy, the more he felt himself becoming trapped in a web he knew he couldn't untangle himself from. She was fresh air after the stifling cloud of perfume that was Hollywood. She was beautiful, talented, and smart, but most of all, she never let her compromised her opinions or principles for show biz. And Cosmo never felt like he was walking on eggshells around her. Looking back, he realised it was when she hit Lina in the face with the pie meant for Don that he'd first fallen in love.

Cosmo knew from the get-go that it was a lost cause. Don had set his eye on something. And when he saw them together, for the first time after the pie disastre, whatever he'd thought before of Don's fantastic stories of the girl whose car he'd jumped into that night, he knew. She'd fallen for Don just as hard as he'd fallen for her. The tensing in his stomach was back, with a vengeance. And this time there was no relief to follow.

Kathy was Don's. And Don was Kathy's. And Cosmo knew that. So he pulled on his cheery face. He was funny, he was silly, and he made 'em laugh. It was the only way he knew how to be. When he watched Kathy and Don kiss in celebration of his own idea for The Dancing Cavalier, he felt that kiss like a bullet tearing through his chest, so he pretended to pout, and hoped his feelings didn't come through. And when she turned and kissed him, with her girlish grin and her lighthearted, 'Oh Cosmo,' all he could do was play the fool and fall back on the couch, trying to bury the storm of conflicting feelings inside, even as it killed him.

So eventually Cosmo Brown found out what could hurt more than watching Don with Lina Lamont. Even as he directed the orchestra in their pit and Don ran down the aisle after Kathy, he finally realised that watching the two people who he'd ever loved together was the most exquisite pain in the world. Because even while he was sharing their happiness at having found each other, his heart was breaking.