‘Wear something less tight around your tits, and maybe I’ll stop…’

Hermione’s jaw drops.

‘I can’t believe you just said that! Apologise at once!’

‘No,’ you tell her, now thoroughly enjoying yourself. ‘I’m only human. If you’re going to walk around flaunting yourself like that, I can’t help looking. It’s only natural.’

‘I do not flaunt myself!’ Hermione’s cheeks are reddening, and dimly, you’re amazed at how good an actress Emma is. ‘How dare you? There’s nothing sexual about what I’m wearing, nothing at all!’

‘Prove it,’ you fire back. Hermione narrows her eyes at you.

‘Prove it? How?’

‘It’s easy,’ you say, reasonably. ‘You take those robes off so I can see a little better, and I’ll unzip my pants. If your tits don’t give me an erection in ten seconds, then you’re not sexy and you win.’

Hermione stares at you – and then tosses her head back. ‘Fine,’ she sniffs. ‘Anything to make you shut up.’

Moments later, your pants are around your ankles and Hermione’s discarded her outer robes. Now she’s just wearing her sweater, shirt and tie, an outfit which fits considerably tighter around her boobs.

You don’t even have to look down to see your cock rising in your underwear. Hermione sees it too, and makes an infuriated sound. ‘Oh, for goodness’ sake,’ she grumbles.

‘Now look what you’ve done,’ you say, daringly. Hermione’s eyebrows raise – and then you’re off the bed, crossing over to her in two quick strides, backing her up a few steps. Her breath hitches, and you can feel her heart beating very fast against your chest.

‘You’ve made my cock hard,’ you tell her, and you’re so close you can inhale her scent. ‘Say sorry.’

Hermione pouts furiously. ‘I will not – ’ she begins –