It's not clear when exactly it happened, but sometimes you look at your little brother and you see a total stranger. It's nothing obvious or in your face; it's this subtle feeling that creeps up on you sometimes.

You come home from university for the weekend because one of your friends is having her twenty-first and you need any excuse to escape from the harrowing hellscape that is medical school. Since you've got time to kill and your parents always want you around, you hang out at home for good chunks of time. During the course of two days, you're actually home more often than Krishna is.

"Where does he go?" you ask your mother while helping her chop vegetables. He's always been social, but his constant absence is quite frankly weird. And okay, maybe you're a little miffed, because even though you understand that you've not been getting on very well lately, you thought he'd at least want to see you a bit when you came back for a visit.

Your mother shakes her head. "You know Krishna," she huffs. "He's got so many friends. I can't keep track of them anymore."

During one of your snow leopard-like sightings of him, you catch him making a Robin costume in his room.

"Who's gonna be your Batman?"

"Go away," he grouses, scowling at you and kicking the door shut.

Early Sunday morning, while you're making coffee in your bathrobe before everyone else is up, he skulks in. Even from a distance you can tell he's been out all night, though you wouldn't need to judge his appearance, would you? What else would he be doing coming in quietly at six in the morning on a Sunday. Left to his own devices, Krishna wouldn't get up before noon; this is a known fact.

"Where've you been, then?"

He freezes at the sound of your voice, and it's comical, it really is. He's guilty, then he's indignant, then he's pitiful. "You won't tell them, will you?"

There is something in his tone that makes it seem like he thinks you will, and ultimately, that's the only reason you don't. Instead, you sit him down and try to investigate what's going on in his life, and where exactly he's going. You've snuck out your fair share of times, of course, but there's something heart-grippingly different about knowing your baby brother is doing the same now. How can he be that old? Fifteen isn't even that old in the first place. And yet here he is, talking about going 'round the pub and drinking shitty lager and talking to girls. Girls. As surreptitiously as you can, you check his neck for hickies. You find two: one peeking out from under his collar and the other at the corner of his jaw. Jesus.

"You're being... I mean, you're careful, right?" you try.

He goes red. "You cannot possibly be trying to give me the sex talk, Leela," he says, distraught. "This can't actually be happening to me. Why are you the worst."

So – yeah, there are apparently a lot of things you don't know about him, and you're really not sure whether that's good or not. You try to remind yourself that you're getting up to things yourself up in Scotland, even with the rigor of your coursework, and that you should unclench.

Girls, though? Really?