He'll use the panties like they originally planned

Even now... there were some boundaries that couldn't be crossed. The young man was a brother before he was an incubus. He knew he couldn't betray Broomi's trust... she'd given him the panties to help him, so those were what he was going to use. Brocken took a deep breath, then draped the soft garment over his wicked, curved member and began to work it up and down with the strength of his clenched fist. The act would have seemed ridiculous under any circumstances, but transformed as he now was, the unfortunate panties were stretched to tearing with every thrust of his penis. The smell nor the sanitary concerns bothered him as he felt a heightened sense of euphoria... The panties were, without a doubt, a much more effective replacement for the habit!

In front of him, Broomi tried to ignore the sounds, while closing her eyes. She had to be here, both to watch the door for any signs of her mom, but also, to verify the results of the test. Still... just behind her, her brother was fapping into her panties. It was a situation somehow far more embarrassing- and frankly, arousing- than actual sexual situations she'd gotten into in the past. The taboo of it- not just a demon, but a demon who was her adopted brother, jerking off to her- was more than she could have imagined. Almost unconsciously, she moved one hand discretely down to her lap and began to rub the spot just above her nether-region, through the thin fabric of her knee-length under-robe.

At the same time, the brother may be using those panties, but he was staring at her while he did so. This was the first time he'd used her panties... and the first time he'd masturbated just next to her, just as importantly. He could feel his dick throbbing, then spurting uncontrollably; the panties did their best to hold it in, but within seconds, his semen was penetrating the cloth. After that, his release wasn't just penetrating the cloth, it was perforating it, tearing the fabric to shreds from the combined **** of his ejaculation and the pointed tip of his dick ramming it.

"Aaaah, shit!" the incubus cried, trying desperately to stop the stream using the tattered remains of the panties. Broomi jumped as she felt something wet hitting the back of her robe. "S-Sis!"

"What? What?!" she cried, turning around in alarm; it was absolutely the wrong move. The boy wrapped both hands around his dick, trying desperately to push it down, but it was no use; her front was quickly becoming covered with that ridiculous shower of demon jizz. "Wha-?! What?!"

"Move, fuckin' move!" Brocken begged her, not realizing it would be just as easy and overall better to point himself in another direction. When the comedic scene was over, Broomi's entire wardrobe was ruined with an untold liquid quantity of her brother's semen. "I... I told you to move," he huffed, sitting back against the room's indented window seat and throwing his head back, depleted.

"This is great!" Broomi exclaimed, sounding excited.

"It's, wuh? It's huh?" the boy murmured, his face becoming beet red as his sister announced that, apparently, being covered from the neck down in his ejaculate was something desirable. "It's what now?"

"I mean, your dick!"

"You think it's...?!"

"I mean, look! It's down!" she explained, pointing towards it while staring unabashedly and wearing a big grin. "We did it! That was the trick! All you need are my used panties... Now we just gotta uh... Figure out how we're going to work disposable panties into my budget..."

Brocken felt touched in the way he often did, thinking about his sister's kindness, as she celebrated their mutual victory even while covered in his stinking incubus bukkake. She had every right to be disgusted with him... but instead, she still saw him as a brother and was working to help him overcome a long-standing problem, so that he could return to his life-long dream of being a knight. "Sis... Thanks," he murmured, while still breathing heavily from exertion. "This... I've never felt so... peaceful." Still... one thing was eating at him... He didn't think it was the panties that were wholly responsible for his successful release. It didn't make sense for the potency of that masturbation to increase so much from just that one variable... As he listened to his sister's jokes, about how she was going to have to burn her whole outfit now... he knew for a fact that it was her presence here that had allowed him to find a temporary respite.

He agonized over the implications of that realization, as he told Broomi to go bathe and let him take care of the clean-up.

"Ha ha! I didn't know you knew how to clean," she teased him... then hurried off, with the image of her nude demon brother... adopted brother... still burned into her head. She felt pretty sure this was going to be one of those baths that was only half about getting clean...

But she really did need to get clean. If her mother saw her now, coated from the bust-line down in hot demon spunk, it was going to open a whole new can of worms.