A/N: I genuinely don't really know what happened here. This was supposed to be a fluffy short thing about Jack and Ianto's first time staying the night in the same bed. It very quickly took on a life of it's on and went down a whole different angsty path.

Left Behind

Jack woke up to the pleasant surprise that Ianto had remained in his bed for the duration of the night. It was a first Jack had been waiting for, for quite a while. It wasn't the first time that they had gone to bed together – that had happened a number of times and was only growing in frequency – but it was the first time that Ianto hadn't snuck off in the early hours of the morning, feeling guilty about moving on so fast from Lisa.

It wasn't like they were moving fast fast – it was coming up to seven months since the Battle of Canary Wharf and almost four since the cyber-incident at the hub – and it wasn't like anything he and Ianto did was planned. Spontaneous. That was how Jack thought of it. One moment they would be talking, and the next, one thing would lead to another and boom; bed.

Each time Jack would fall asleep, smiling contently to himself at Ianto's mere presence beside him. He would fall like a giddy child with a schoolboy crush. It was a feeling he hadn't experienced in a long time. Of course, he'd had many one-night-stands, flings, and friends-with-benefits situations over the recent years but this – whatever it was– felt like there something much more to it – whatever that was.

And every single time that Jack woke up to find Ianto gone, he wondered whether he was being incredibly stupid. He wondered whether Ianto was just using him; as a rebound? As a distraction? As some kind of escape from his gloomy reality?

And then Ianto would arrive at work later in the morning with a box of Jack's favourite donuts under his arm and voicing profound apologies for leaving. Such actions immediately made Jack feel guilty for his earlier train of thought and he would make sure that Ianto knew that he understood, that it was fine, and that grief was only natural.

Of course, Jack did fully accept that it would take Ianto time to move on from Lisa. She had been such a huge and integral part of his life to the point where Jack certainly wouldn't be surprised if he learned that Ianto had been preparing to propose to her. He'd seen the pictures, as the team had sorted through the wreckage of the basement during Ianto's suspension, and he had seen the love captured in both of their eyes in a moment forever frozen in time.

And certainly, his situation with Ianto was nothing like that. Their own situation was messy from the get-go, and it was plainly obvious that neither had a clue as to what they actually wanted from it, or where they wanted it to go.

All Jack had known was that he wanted to wake up to Ianto still sharing his bed – so desperately he would even forgive him if he turned out to be the type to hog the duvet – because that would show progress. Progress towards what, exactly, he had no idea, but it would be progress towards something.

On that mid-January morning, Jack had received that first progressive step he had been after for so long. For the first time, Ianto was still there, and yet it was nothing like Jack had been expecting. For while Ianto was indeed still in the bed, fast asleep, Jack couldn't help but feel like the Welshman would rather by anywhere else.

In fact, Jack wasn't even convinced that Ianto could technically be classed as in the bed.

With the small space Jack had to work with in terms of his sleeping quarters, he had been left with little option but to have his bedframe pushed right up against the wall. Ianto lay on that side of the bed – as far on that side as humanly possible – with his body pressed right up against the cold metal of the wall. If the wall wasn't there, Ianto would certainly be on the floor. If Ianto was a ghost, he would be halfway through the wall.

Jack had always thought of bed sharing as a slightly more intimate affair – sharing body warmth with arms wrapped around one another and legs entangled – but Ianto was giving him none of that. The frequently arising question popped into his head again; was he just a distraction from Lisa?

Jack couldn't keep up. He couldn't work it out. Most of the time with Ianto, it worked, it felt real and passionate and easy. He would always go to sleep on cloud nine. It was waking up – the mornings after – when things felt wrong and difficult. For the first time, on that morning, the cloud nine feeling had maintained when Jack had woken up to Ianto fast asleep in his bed. That was, of course, until he had clocked the way in which the Welshman was sleeping. Then Jack just felt… unwanted. It was a feeling Jack was largely unaccustomed to feeling. And he hated it.

When Ianto stirred awake, he first looked dazed and disorientated. His blue eyes eventually met Jack's, and Jack could almost see the pieces being put together inside his head.

"Morning," Jack greeted.

"Morning?" Ianto questioningly mumbled the greeting in return as he lifted his wrist to look at his watch. "Oh, wow."

"Yeah, you stayed the night," Jack stated flatly. "Was that not the intention. Were you planning on running off again in the middle of the night?"

"It's not like I plan to do it!" Ianto immediately defended himself as he sat up, leaning back against the headboard. "Well, I guess I do. And I know it's not fair on you, but I can't bring myself to-"

Ianto cut himself off with a deep breath in. His hands went to either side of his head and started rubbing his temples. He let out a loud, frustrated sigh.

Jack shuffled over slightly in the bed, moving beside Ianto so that their shoulders brushed against each other. He placed a hand on the younger man's arm.

"Come on then, tell me what's going on in that brain of yours," Jack prompted. "This is more than just feeling guilty. Frankly, you seem…"

He trailed off, not really sure what word he was even going for.

"Scared," Ianto finished for him, raising his head from his hands at the same time. "I'm scared of history repeating itself. Ever since the Battle happened, it takes me ages to get to sleep at night. The memories haunt me at first and then my thoughts are left to wonder. They wonder ahead to the future and what would happen if Torchwood Three got destroyed like One did. What if everyone else here dies too? What if I'm the sole survivor? And what if whatever it is we have, Jack, gets lost the same way I lost what I had with Lisa?"

"The harsh reality, Ianto, is that there are very few certainties in life but what's the point in living life worrying about what might be and torturing yourself with what-ifs? That isn't life. Trust me, I've done it, it's not fun," Jack told him. "Life is just about taking each day at a time and if you're spending that time worrying about the future, you're going to miss what's right in front of you. Wouldn't that be tragic?"

"I just can't do it again, Jack," Ianto maintained, shaking his head. "I can't be left behind."

"Hey, come here," Jack urged. He pulled Ianto close to him, wrapping his arms protectively around the younger man as Ianto's head settled against his chest. "I can promise you one thing; it won't happen to you again. I'm never going to leave."

"You can't make that kind of promise-"

"Ianto, I can't explain how I can promise that but I can. Trust me," Jack insisted, "I'm never going to leave."

It was with that statement that Jack realised why he was so reluctant to put a name to whatever it was he and Ianto were starting. He had been in relationships before and, ultimately, they had all ended virtually the same. Either the other person had died young or grown old and died. Either way, Jack always ended up alone again… left behind.

His immortality meant that one day Ianto would grow old and grey and then die and, when that day does come, Jack will still look as he had for the last century. A lot of people longed for immortality. Jack longed to grow old with somebody, just like his grandparents had done.

With his immortality, there was no chance of that. The only certainty was that he would end up alone over and over again.

Ianto wasn't the only one who kept running away from whatever it was they were starting. Jack knew he was doing it too. On at least three occasions he had backed out of asking Ianto out on a date and it wasn't because he was afraid of getting turned down.

Ianto had said it best: I can't do it again. I can't be left behind.

Jack didn't want to get left behind either. Not again.

Barely even a week later, Jack heard the all-too-familiar hum of the TARDIS. The Doctor. A one-hundred-and-thirty-nine year wait for the Doctor had come to an end, and with brilliant timing.

Because the Doctor could fix him.

Jack had always been so sure of that. Whatever it was that had left in the state of never dying, the Doctor would know how to stop it. And Jack would be free. He wouldn't have to worry about getting left behind, not by Ianto, noy by anyone. His life would eventually come to an end, just as it was natural for every life to end.

Suddenly finding somebody to grow old and grey with seemed entirely plausible. Maybe that someone could even be Ianto? And so he ran, faster than he had ever ran before; he ran to the Doctor, not just for him but for Ianto too – whatever it was they had.

It wasn't until much later, on board the Valiant, under the imprisonment of the Master, that Jack truly realised what he had done. In his rush to get to the Doctor, his excitement at the thought of a mortal life, he had done exactly what he had promised Ianto he would never do. He had left.

For a whole year, the Master took joy in thinking up all sorts of new and disturbing forms of torture for Jack. Nothing he could think up rivalled the torture Jack put himself through.

Ianto's voice played on a loop inside his head, "I can't do it again, Jack. I can't be left behind."