He plays at sword fighting with both children at the same time, two wooden swords taking on his one. He's better at using his left hand now; practice has made his arm strong, has smoothed out the tremors in the muscles, and has quietened the shaking of his hand under the weight of his sword. The strokes are harder, more elegant and much more precise than they ever have been before.

But when he fights with the children, he'll let them best him… eventually. It's a steady rhythm - block, block, hit - and will usually end with Aelinor giggling as Jaime sinks to his knees in mock-agony and begs for the mercy of the Great Lady. Lucias, meanwhile, is already tugging on his sparring partner's sleeve, attempting to haul him to his feet so they can begin again. I know you're letting us win, Ser Jaime, Luca will protest and Jaime – not for the first time – curses their intelligence.

(It doesn't take much effort to summon the memories that make his writhing on the ground a wholly believable display, but Sansa will pay for it later when she is disturbed from her sleep as Jaime relives all those memories in his. She'll smooth his hair back from his feverish forehead, and kiss his wrist, and wrap his arms around her before tugging him into her embrace until there's not a breath of air between their bodies.)

Jaime bows his head to Aelinor and, being that they are almost the same height when he kneels in front of her, she will place a small hand on his shoulder and bid him, Arise, Ser Jaime. And he, like the obedient servant he is, follows her command.

Aelinor and Lucias; his children, the ones he was allowed to love. Their names were chosen carefully, Jaime remembers, neither being obviously Stark nor Lannister. A clean slate, Sansa said, for the future. He had almost retorted that she was dreaming if she thought their names alone would keep them safe in this world, but he swallowed it before he could crush her optimism. There wasn't much of it to go round, after all. Besides, their names might not offer them any protection – they were still Starks, and things were still precarious – but he will, this time, and he will do so fiercely.

It's Aelinor that comes to him first with her queries. A clever girl, getting more observant by the day (Tyrion would laugh, Jaime thinks, and tell him that Aelinor and Lucias are the first perfect Lannister offspring for a generation, having none of the inadequacies that they and their sweet sister so frequently displayed, and remarkably more redeeming features), and it is she who can't help but notice the similarities between her twin brother and the only other truly fair-haired man she has known. She climbs into Jaime's lap, her own hair the most vibrant of reds where the light from the fire reflects off it, and asks him outright.

'You're Luca's father, aren't you?'

Sansa's hand stills over her embroidery for a second, but she doesn't look up. Jaime will be left to his own wits with this one, apparently, and he can't help but wonder if Sansa knew this was coming.

'And if you're Luca's father, and he is my brother, that must mean you're my father too.'

'It doesn't always work that way, my sweet,' he replies, jumping at the opportunity to shift swiftly to a new topic, any topic.

Aelinor, however, is undeterred, 'No, I know about half-brothers and half-sisters. But, Lucias is my whole brother so we must have the same mother and father. And we must have a father, or our name would be Snow.'

But your mother wasn't bedded by a Stark, he thinks wryly, and yet you bear that name, little one.

However, he decides this is no time for sarcastic remarks and evasiveness. He can't dally around her questions like he would with an adult because, in all honesty, she's far more intelligent than most adults he's encountered, not to mention that she is relentless. He thinks about how best to explain to her that yes, he is their father, but no, she can't go around shouting it because he is a Lannister and, does she understand what it means when her mother says there must always be a Stark in Winterfell?

He doesn't know how to tell her that should their mother die, the North would never rally to a Lannister heir in Winterfell. The Lannister children, along with their father, would be shipped out, taken prisoner, tortured, or killed before the last traces of warmth had even left Sansa's body. The Stark children, however, would be out of harm's reach, and Jaime finds he doesn't care what happens to him, or anyone, as long as they are safe.

Sansa has tried to rationalise with him about this before. They already know. Everybody knows. How could they not? I gave birth to a set of twins, Jaime, twins. And just look at them.

He looks at his daughter, her eyes so like his own, and can't bear to think of her bleeding and broken, cold and grey, totally at the mercy of merciless men. The very thought fills every square inch of him with a burning fury as if it had already happened, as if he was looking at her mangled form in his lap instead of her whole and healthy body. After all this time, and despite all his left-handed practice, he can still feel his phantom right hand anticipating the grip of his sword. He is all too aware of its desperation to tear down her would-be murderers, to submerge Winterfell beneath the blood of them.

Has nobody learned, he imagines himself screaming as he clutches her corpse to his chest, has nobody learned that children are innocent?

'Listen to me, my Lady Aelinor. You are strong, and brave, and good, and clever. But, most importantly, you are all those things without ever having known a father, so it is my opinion that you would continue to do very well without one.'

He sees the protest rise in her throat, so he presses on quickly.

'You may not call me your father, but you must always know that I will protect you and treat you with honour. Can you live with that?'

He watches her thinking his proposal over, can almost see the words flitting across her face as she considers them. Jaime sneaks a look at Sansa, to see if her expression will give him any clue as to whether he was right or wrong in his choice of words, but she seems to be curiously absorbed in her stitching and apparently paying them no mind at all. Aelinor, at last, with a hand against his cheek (so like her mother) and in a tone far too grave for her number of name-days, asks him,

'Do you swear it?'

'I do,' he answers solemnly, without a hint of hesitation. And this is the first oath he's made that doesn't conflict with anything at all.

When she leans closer to whisper in his ear, he takes her hand from his cheek, wraps his fingers around it and presses the tiny knuckles to his lips. She quietly asks (but not so quietly that Sansa misses it, evidently, for Jaime can see the small smile playing on her lips when her daughter speaks),

'Do you think I may call you father in secret?'

Jaime kisses her knuckles again. Yes, he decides, this is the work of Sansa Stark.

'You may,' he concedes, eventually, 'But only in very great secret. When it is just we two.'

That night, Sansa loves him slowly and languidly, and he sinks deeper and deeper into the mattress as his muscles relax under her touch. When she is over him with her lithe thighs on either side of his lower torso, her hands smooth upwards over his bare chest, then his shoulders and neck until her fingers thread themselves into the hair at the back of his head.

Mischief dances in her eyes as she informs him that she needs a daughter in her belly soon, please, since he has quite stolen the one she already has. He laughs and flips them both over so she is pinned beneath the weight of him.

'I can't steal what is already mine.'

But when she crosses her ankles across his back to clamp his hips between her calves, digging her heels in to his lower back, he promises to make it so.