Age 16:

Things between Jack and Manara had been good, but they never did recapture the spark that had led them to their first session. After a few months they realised that they were too young and inexperienced to try and date, and decided that they would just be friends. They did know how to make enough money to get by, and even make themselves comfortable in their new digs.

After a few months of various grifts, a few smash and grabs, Manara met someone in a bar and brought him home. Jack didn't care, she and Manara only had sex occasionally anyway, and separate rooms meant they had privacy when they wanted it. They had loud and passionate sex the first night, and Jack was surprised when he was still around when she woke up near noon.
"So, who are you?" she asked gruffly.
"Name's Xarc."
"Jack."
"So, what's your story?"

"All you need to know is that I'm a biotic, Manara's friend, and I don't like you right now." He handed her some toast he had just made. "Alright, so I dislike you a little less now. Doesn't mean we're friends."
"Point taken," he said with a nod. "So, what's your attitude to crime then?"
"If someone else has what I want, and I can take it, I do. Simple as that. Manara helps me to pick my targets."
"That's cool. You two looking to expand your operation? I know some pretty soft targets that would make a fat payoff."
"Could be interesting," Jack replied, munching on her toast.

"So, we're all cool on the plan?" asked Xarc.
"Peachy, now let's get on with it, it's breezy out here." Jack shivered a little bit.
"Well maybe if you wore something a little more covering, you wouldn't have that problem."
"But then I wouldn't be the little ray of sunshine in your life," she quipped back at him.
"And we wouldn't want that now, would we?"

Manara was crouched down, omni-tool flaring as she dealt with the security systems.
"If you two could stop bickering like an old married couple, could we please get in out of the wind?" The three of them entered the now unlocked door and closed it behind them. They were in the back room of a jewellers, the three of them looking through the boxes and cases of cut and uncut stones. Xarc knew more about this kind of deal, so he was able to point them to the most valuable pieces. While Manara disabled the electronic security on the cases, Jack used her biotics to lift the stones out, leaving no evidence for nosey police to look for.

Hours later, after successfully converting the stones into hard currency through a fence Xarc knew of, the three of them were at their place, getting thoroughly buzzed. Between the banter and the lusty looks being exchanged between all three of them, what happened next was almost a foregone conclusion.

The sex the three of them had in the large bed was fantastic, long and extremely pleasurable for all parties involved, and they eventually collapsed in mutual exhaustion, wide smiles on their faces.

It had gone well like that for a while. The three of them would pull off jobs they would never have been able to without each other, enjoying massive profits for relatively little work and risk. Occasionally they would have another threesome, but more often than not it was just Manara and Xarc, while Jack went off on her own. She'd go find someone else to fuck, or just drink and dance the night away. But tonight, everything changed.

Jack had gone off on her own again after a particularly big score. They'd robbed an armoured car, relieving the driver of his heavy burden after knocking him unconscious. Xarc and Jack wanted to off him, but Manara was insistent, so he lived. They didn't need to convert much of it through their fence, and Jack wasn't feeling particularly in the mood. Something about it had bothered her for some reason. Maybe it was the short look of anger on Xarc's face when Manara had disagreed with him. Whatever it was, she just felt the need to be alone for a while.

She came back in the small hours and went straight to her room, kicking off her boots and falling onto the mattress in a dishevelled heap. Normally she didn't particularly care about any and all sounds coming from Manara and Xarc's room, but tonight it was different. It wasn't the loud moaning or euphoric post-coital whispering, it was a softly spoken argument. Normally that wouldn't have bothered Jack either, but her earlier feeling about the look made her curious. She walked over to the window and leaned out, able to hear what was being said clearer.

"-what are you talking about Xarc?" asked Manara.
"I'm talking about redistributing the payoff next time. We won't need her for this job," came the stern, and slightly slurred response.
"Jack's my best friend Xarc, I won't agree to this."
"Who said I'm going to leave you a choice?" Then there was some muffled footsteps and whispering, but Jack wasn't able to figure it out. She did hear a gasp, probably Manara, but she didn't know what it was in response to. Then she heard her friend again.
"A-alright Xarc, we'll do it your way. Jack won't get a cut of the next job."

Jack bit her hand to stop the sound of her sob, closing the window and heading back inside. She couldn't understand it; her only friend was setting her up! After a few hours of tears, a steely look of determination crossed Jack's face. If her friend was going to do this to her, then she would get in first. She stalked silently to the kitchen and grabbed out a sharp knife, hefting the blade in her hands to feel the weight. This wouldn't be the first time she'd killed, but it would be the most personal.

She stalked silently across the floor to the door to couple's room, checking for the sounds of sleep. Hearing nothing but breathing, Jack pushed it open and slipped inside, hiding the brightness of the blade in her shadow. She padded over to Xarc, who was laying on his back, an arm hanging over the side. She walked right up to him, wondering what it would feel like, before she pressed a hand over his mouth and ran the blade quickly over his exposed neck. His eyes opened in shock, but by the time he realised what had been done, lack of blood and air were already killing him. Jack just watched the light in his eyes die, feeling the familiar warm feeling she got from her conditioning early in life.

As he lay there, still and bleeding, Jack moved over to Manara, on the other side of the bed and facing the wall. The warm feeling was gone now, and Jack felt a momentary twinge of guilt for what she was about to do. She moved the other girl's arm out of her way, forgetting how light a sleeper she was. Manara's eyes opened and she saw jack, red-bladed knife in her hand.
"Jack, wait -" was all she had time to say before Jack stabbed her in the chest. "I'm... sorry..." she gasped with her dying breath. Jack didn't feel anything, seeing her hand still holding the knife sticking out from the older girl's chest.

Then an overwhelming need to run overcame her. She went to her room and gathered as many of her things as she could carry, before opening the door and running out into the night air, tears streaming down her face. Why Manara, why did you betray me like that? her only repeating thought.