This is an AU which ignores Legend of Tomorrow and assumes Barry didn't go back in time at the end of Season 2.
The thing about Barry was the kid wore his heart on his sleeve. Therefore, it wasn't difficult to detect when something was wrong. For example, right now the kid's teeth were clenched tight and his shoulders were sunken, as if he were carrying the weight of the world on them. Which, when Barry was concerned, he likely was, warranted or not. His lanky arms curled loosely around his body, barely refraining from wrapping themselves protectively around his chest. Something had clearly happened.
"Looking a bit glum there Scarlett. Fail to rescue a kitten out of a tree?"
But of course, he was Captain Cold and Captain Cold couldn't just ask the Flash what was wrong in a kind, civil manner. They both had reputations to maintains, after all.
However, rather than give the weary, woebegone retort Len had become accustomed to when the kid was in a mood like this, pure anger flashed in those dull, hazel eyes.
"I don't want to hear any of your shit Snart."
The expletive from the otherwise PG-13 man made Len start but he wasn't thrown enough to not notice that hidden beneath rage was a lace of pain and anguish. Evidently, this was no common heroic moral dilemma the kid was struggling with. Something had happened. Something big.
"This wouldn't have anything to do with that 'speedster race' the news talked about, would it?" Len probed, despite common sense advising him to drop it. For once, Len was choosing selfish desire over logic.
The things Barry did to him.
"I said cut it out!" Within milliseconds, Len was pressed hard against a wall, Barry's hands gripping his parka tightly. Under any other circumstances, Len would think his secret fantasy was about to be played out, but alas, it wasn't a move of passion but anguish, if the tears lurking in the corners of Barry's eyes were any indication.
"I'm simply asking you what the matter is. I know you well enough to see something's eating at you," Len replied calmly. A quick glance showed no one was around; he could afford to drop his image a little.
Barry scoffed darkly, removing his hands from Len in order to begin pacing. "You don't know anything about me Snart."
"Au contraire, I know you are Barry Allen, 26 years old and you work at the CCPD with your adoptive father Joe West. But those are just facts. I also know that your forehead scrunches when you're trying to solve a problem, that you're a regular at Redling's Bar for their karaoke night. You have a ridiculous collection of mugs, thank you for the reindeer by the way, and you drink your coffee with obscene amounts of sugar. I know you have a heart too big for your chest and a guilt complex a mile long. So, still think I know nothing about you Scarlett?"
Barry froze; digesting Len's little speech in stunned silence.
"…How did you know about the coffee?"
Len tapped his nose. "Can't go around giving away all my secrets, can I? So, c'mon kid. Spill."
"It's none of your business." Ah, but he was wearing Barry down. There was still a spark of defiance but it was not of the scale of his previous anger. Just a bit more…
"Maybe not, so who better to tell than an unbiased, outside party? What guilt are you harbouring this time?"
Before he could blink, Len felt the brief sensation of being cradled in Barry's arms before he was deposited with a thump in an empty warehouse.
"Sorry, I just, I wanted to take this off," Barry explained, throwing his cowl on the floor. "I don't really want to be the Flash right now."
Len gave a considering nod. "Alright Barry."
The kid's eyes widened, but whether it was due to the use of his name or his easy acceptance Len couldn't tell. Either way, it didn't matter. If the kid wanted to be Barry, then he might as well be Len and Len was a good listener, especially when it came to people he liked.
"Okay, right then." Barry ran a hand throw his hair and seemingly unsure with what to do with himself, he began to pace once more. "So, you know about Zoom."
"Pretty hard to miss," Len replied wryly. When Zoom rose to power, Len made the executive decision to lay low. Mick tried to convince him to at least consider the prospect of joining up with the monster but even despite Zoom being far too…extreme for his tastes, Len had faith that the Flash would deal with him (Len will never admit to how scared he was when he saw the broadcast of Barry in that thing's grip).
"Well, he turned out to be Jay Garrick. I don't think you met him."
Len thought about it. "Lis might have mentioned him. Blonde guy?"
"Yeah, well, he was from Earth 2. Wait, I should probably explain that…"
What followed was a tale of parallel universes, doppelgangers, deception and heart-ache. Len knew the kid lived a complex life but never could he have predicted this. If Len didn't know the kid was too honest for his own good, he'd think it was complete and utter crap. This was why Len refused to go into the hero business.
"And that's when Zoom killed my dad," Barry said, story beginning to wind down. The speedster's voice had grown hoarse and clogged with emotion. Len longed to reach out to him as he'd often thought about in his late-night, indulgent, daydreams but he refrained. He'd done well so far, just a little left to go.
"He said it would make us alike and that my inability to kill him, to be selfish, made me weak. I wanted to kill him. I wanted so, so bad to take revenge. But I didn't and then the other's locked me up for a while because I was 'emotionally uncontrollable'. Barry gave a dark laugh full of self-loathing that made Len wince internally. "They were right. Anyway, Joe then got taken and Zoom used him as leverage. He wanted us to race to provide power for this Puslar he'd created to destroy this Earth. I raced him but instead of powering it up, the time wraith's came and they destroyed Zoom. Later, we found out the guy in the iron mask was the real Jay Garrison and get this. He looked just like my dad. He was my dad's doppelganger. Harrison and Jesse went back to Earth 2 and that's about it. I trusted the wrong guy and not only did I nearly help destroy this Earth but I got both my dad ad Earth-2 Joe killed." Tears that had briefly dried up returned again and this time, Len didn't hesitate in standing and putting a hand on Barry's shoulder.
"Jesus kid," Len breathed, still trying to wrap his head around everything. It wasn't often that Len found himself at a loss of words but this was a special circumstance. He settled for focusing on the bit he understood. "You didn't get anyone killed Barry. That's all on Zoom and his minions."
"Is it though?" Barry asked wetly, leaning into Len and Len readjusted them so he had an arm curved around the speedster's shoulders. "You know, I thought about going back. Again. If I saved my mom, I'd get a life with both of them. None of this would've happened."
"But you didn't. Why?" Len wondered what he'd do in that sort of situation, if he had a way to make it so that his mom was still around and Lewis out of the picture, but risking the timeline.
Turns out Len isn't as selfless as Barry.
"Because…because I still had a good life with Joe and Iris. It's not fair for me to change their lives, and everyone else's. I know my mom and dad loved me and they wouldn't want me to risk it. Even though I wanted to, still want to." Barry's shoulder's shook and Len gently settled them both on the dusty floor. Barry's head came to rest gently beside his.
"You're a better man than me kid, though you knew that already. Listen, I don't know exactly what to say but this guilt you're carrying? You don't need it. Hell, you saved the whole world Barry. What happened to your dad was awful, but it's not on you. Zoom did that and you stopped him. You did good kid. You did good."
Barry said nothing, only continued to cry softly and Len let the kid grieve in peace. It may have been minutes, or hours, later but the tears eventually subsided and Barry gave a wet laugh.
"Sorry about that."
"Don't worry about it kid," Len dismissed. It may not have been how he thought the evening would go when he and the Rogues set out to fight for their turf against a rising gang, but Len couldn't say it was wasted time. Far from it. "So, do you want this to be something we forget about?"
Barry shook his head, giving Len a look that, for once, he couldn't discern though he felt the faint stirrings of hope form within him.
"No, actually, I…I want to do something. And if you don't want to do it, just say."
Len remained silent as Barry slowly leant in and pressed his own salty lips against Len's own chapped ones. Carefully, Len raised a hand and put it on Barry's neck and the kid took that as permission to deepen the kiss until Len felt like the air was being knocked out of him in the best way possible. All too soon it was over, but it was a fair price to pay to see Barry's flushed, smiling face directed solely at him.
He may not know where they stood now but he was damn well excited to find out.