His affairs.

'It seems like you're always seeing someone, big brother.'
'Well... not right now I'm not. Besides, it's not like relationships are what they're cracked up to be.'
You smile. 'Um... have you ever...?'
'Have I ever what?' He asks.
'You know... with a girl?'
'I've done lot's of things with girls, J. What do you mean?'
You see the playful glint in his eyes. 'Oh, you know what I mean!' you say, blushing.
He chuckles. 'Sorry, sis. Yes, I've had sex with a few of my girlfriends. Why do you ask?'
'Oh... no reason...' You say. 'um... what's it... like?'
'Well, it's different for girls, but it's nice. Especially if you really fancy your lover.'
'Oh... I see.'
'Don't worry, J. I'm sure you'll try it soon enough. And, if the guy doesn't treat you right, he'll have me to deal with.' He smiles, lovingly at you.

The car pulls up at the school. You and your brother get out. He gives you a quick hug and heads off to find his friends. You run over to your friends, Amy, Alice, and Josh.

'Hey, guys!' You say, running over to them. Amy gives you a big hug as Josh andAlice say "Good morning".

'Hey, J! You and Alice should come round my place tonight! My pony's finally big enough to ride!' says Amy.
'Really?' You reply. 'That's cool!
'I know! Besides, it's been a while since we've had a sleep over, so I thought this would be a good excuse.'
Alice nods in agreement. Josh walks up behind you. 'What do you girls do at those things, anyway?'
'We stay up late and talk about which of our guy friends would make the best couples.' chirps Amy.
'So... you talk about exactly what we do at a guys sleepover?' Josh jokes.

You giggle, thinking about how that would work. Just then the bell rings. Amy makes a comment about class starting and you run into the school. Unfortunately, you and Alice have P.E. first thing.