'Dad?'

'Yeah, buddy.'

'I have a question about babies.'

Castle felt his insides go icy as he held the door open to Alexis and Shane's building for RJ and Jojo; they'd bundled up in their bright winter outerwear so extraordinarily they looked like Angry Birds extras. 'Yes?' he asked with some trepidation.

'How will they know when they are lefties or righties like Alexis?'

'Oh, ah, good question.' Castle unclenched, shakily let out a breath as he took a moment to think it over. 'I think babies just know which one they wanna use, what feels best for them.'

'Could you tell that Alexis was gonna be a leftie, Daddy?' Jojo inquired, stretching up to punch in the intercom code for her sister's apartment.

'Actually I could, when I'd pass her something like her spoon or her crayons, if it was in her right hand, she'd swap it to the left.'

'But...then...well...'

'Well what, missy?'

'If Alexis is a leftie and Petra is a righty, won't that hurt their mumum-baby bond?'

'Not at all. Did my daddy-daughter bond with her get hurt?'

'Not at all,' RJ echoed, then jumped when Alexis' voice came through the speakers loud and clear asking who was there. 'It's your friendly neighbourhood Justice League!'

'Hey guys! Come on up!'

The door buzzed and a short moment later they were on the Weaver doorstep with Alexis cuddling Petra close while the beautiful little redhead sucked heroically on her pacifier.

'Hi there Alexis! Hi Li...Petra.' Jojo turned as pink as her neon scarf as she corrected herself. 'You are getting big, and you look very pretty in your cozy clothes.'

'Yes, these were a gift from Auntie Lanie and Zio Dave, weren't they?' Alexis gave her baby a happy jostle, making Petra smile around her soother, and fussed at the adorable flannel pyjama set in Quebecois tartan. 'They visited Dave's family in Montreal for a ski weekend and Violet insisted on bringing these back for my pretty baby girl.'

'Blb!' Petra burbled, stretched towards Castle who melted like butter. 'Blb?'

'Let's let him get his boots off, Petra,' RJ giggled, 'but I'm already done so can I?'

'Park it on the couch first, hot shot,' Alexis told her brother, and RJ, having learned of the perils of an annoyed female after daring to put the wrong sundae sauce on Trini's ice cream more than once, did as his big sister instructed. When Petra was placed on his knee, RJ kept his hand tenderly on the back of her head and spoke to her just as he had with Jojo when she'd been a baby.

'There we go, tiny lovely girl, yes you are tiny and lovely aren't you? And you're getting so big, oh and no earrings yet, I see.'

'Not until she's at least a year,' Alexis agreed - and what a row that had been with Shir; she'd lost track after her mother-in-law had reverted to Hebrew in her ire at the idea of her beautiful granddaughter being punctured for the sake of style before she could dress herself. 'Maybe that's something you and she could do together, Jojo.'

'Oh that would be fun, Alexis,' Jojo breathed, 'we could have a Castle girls spa day! You, me, Mumum, and Baby Petra! We can get nails and face-ohs and hair and ears done!'

'Facials, Jojo.'

'Oh yes, of course Alexis.'

Alexis just shook her head, turned on the kettle before joining her family in the living room. 'To what do I owe this surprise, you guys?'

'We have the day off, and felt like seeing our best girls, and we figured since it is so cold we would come to you,' RJ explained as he instinctually shifted Petra so her back rested against his chest and he wrapped his arm around her middle to keep her safe, 'since it is far too cold out for our pretty princess Petra.'

''Xactly,' Jojo agreed with a grin. 'Petra's getting so big already but she isn't that big yet!'

'She will be six months old soon.' And oh where had that time gone, Alexis thought with a little wistful sigh.

'How soon?'

'Very soon. In fact, Shane and I were thinking of having a little party for her to celebrate being six months old. Nothing big or overwhelming since Watkins is going to burst soon and no one wants to miss that.'

'Yes, the baby boy will be here soon!' RJ grinned, then frowned again. 'How will that work, having two mumums? How will they know how to teach him how to use a toilet like a boy? Or shaving? Or doing sports?'

'Hey!' Affronted, Jojo snapped the word at her brother with such ferocity that Petra gave a jump on RJ's lap, nearly slithering off his knees. 'Girls can play sports just fine!'

'Of course you can, but there are certain things that a guy needs his dad for, right?' RJ looked first to his father for confirmation, then to Alexis. 'There's gonna be girl stuff that Alexis will understand to teach Petra because she is a girl too, right?'

'Exactly RJ,' Alexis said, hoping Jojo's ruffled feathers would smooth down; as if on cue, the tea kettle began to whistle and Alexis popped up from her chair. 'Who wants a hot chocolate?'

'Me! May I help Alexis? RJ has mono-popo-lied the kitchen now,' Jojo asked, casting Alexis a doleful look. 'I never get to help now, unless Mumum makes him let me help.'

Alexis looked over the little girls head, saw Castle and RJ both shaking no and Petra moving her little head back and forth in a perfect imitation of her uncle. 'Alright, I suppose us girls have to stick together, huh?'

As two of his favourite redheads wandered into the kitchen to fix up treats for the house, Castle leaned over to RJ and whispered, 'See, I told you Alexis wouldn't suspect anything. She will be super surprised when she finds out what we have planned.'