Everyone's fine with it.

John swallowed as the doctor explained, his eyes gliding back over to Louise’s. He was shocked to see that she, too, was looking at him, and biting her lower lip. She still had her fingers on him, though she’d stopped moving them, and when the doctor finished speaking, she looked over and dropped her jaw.

‘I am,’ John said, still watching his little sister. Her reaction to his agreeing only made him harder, her cute features veiled in disbelief that he was okay it the doctor’s suggestion. Both he and Doctor Harper now waited for her response, though one of them more eager than the other.

‘I,’ Louise began, looking down at the prize in her hand. While she thought, she moved her fingers down her brother’s shaft to the base, causing it to twitch. ‘Of course,’ she suddenly announced, clearing her throat. ‘Me and my boyfriend do it all the time. If it’ll make him feel better, of course I’m okay with it.’

John exchanged a look with Louise, confirming with her that she knew what she was agreeing to, and secretly hoping she wouldn’t refuse now. With a small nod, she licked her lips and one corner of her mouth raised in a cheeky smirk that sent waves of blood to John’s already concrete erection.

‘Very well.’ Doctor Harper retrieved something from her desk, handing it to Louise. ‘Try to get as much into this as you can, so that I can perform a few tests later. Now, I know it may be a little uncomfortable having me in the room, but I’m afraid I’ll have to insist that I remain present for the process, to take note of any oddities that might help determine the cause of John’s pain. Is that okay?’ Louise nodded eagerly, followed by her brother. The doctor’s presence was the least of their concerns. In fact, having her there only confirmed that what they were doing was okay and not wrong like it should have been; a professional was advising them towards it. ‘Great. In that case, please, just act like I’m not even here, and continue.’

Louise nodded and looked back to her brother, first his face, then down to his swollen manhood between her fingers. She moved her light grip back up to the head of his shaft, then back down, stroking so slowly it almost hurt. A small drop of precum formed on his busting head.

‘What’s that?’ she whispered.

The question caught John by surprise. ‘It’s… precum,’ he stammered, watching his sister glow with confusion. ‘You can… rub it around. If you want.’

She glanced up through her fringe at her brother, the curiosity in her eyes reminding him how adorable she looked. Louise followed his advice and, using her thumb, rubbed the ooze around the sensitive head. ‘Like that?’ she asked.

‘Perfect.’ John couldn’t believe what he was congratulating his sister for, but the thought soon disappeared as she finally brought her whole hand forward, wrapping her fist around his shaft. Slowly, as if taking great care, she moved her hand up to his head, and back down, pumping a few times with awkward lack of confidence, before gaining a bit more of a rhythm and beginning to masturbate him.

‘How’s that?’ her voice squeaked, looking back into John’s eyes.

He swallowed at the sight of his little sister jerking him off, and leaned back on the table with the feeling of her small, warm hand gliding up and down his boner with a carefully increasing pace.

‘Amazing,’ he answered, never taking his eyes from her gorgeous face covered in excited curiousity.

‘You can touch me,’ she whispered. ‘If you want.’

‘What?’

‘If it’ll help you…’ she explained, moving her hand faster, throwing waves of pleasure over him. ‘You can touch me. I don’t mind.’

John understood what she was allowing, and though he knew it was unlikely he’d last much longer with her help anyway, he wasn’t about to pass up the opportunity to fondle his beautiful teenage sister’s body.