Other than a single brief bit of discomfort, Carla was pleased with what her brother was doing with his hands: his touch was as gentle as she could have wished for, and he was somehow able to bring out sensations in her breasts that she'd never experienced on her own. Then when he started playing with her nipples, those feelings increased even more, and she could feel her nipples grow longer and harder under his ministrations. Completely forgetting that it was her own brother molesting her, and that the two of them had an audience, Carla felt herself begin to get aroused from what was happening to her developing mammaries.
Without being told to, Robert cupped his sister's breasts in his hands so that he left their peaks exposed, then leaned forward and took the end of one mound between his lips. Carla gasped in response, and when he started to suck on the woman-flesh in his mouth, her pleased moan was so soft that he was the only one to hear it, he was sure. It was short work for him to bring both of her nipples to full extension, glistening with his saliva.
Carla had never been able to bring her nipple and tongue together, never mind actually experiencing having any part of her boobs in someone's mouth. The feel of Robert's mouth around her nipple had been indescribable; when he actually began sucking, the sensation only got better… something she hadn't thought possible.
Robert was having the time of his young life when he heard their captor tell him "I think you've had enough fun, junior. Now it's time for you to learn something you'll like even better."
Reluctantly, Robert pulled his head and hands away from Carla's tits. He caught the brief look of disappointment on her face before turning his head to look at the man with the gun while he waited to hear what was next. He couldn't believe his ears when he heard the man ask "You've heard about eating pussy and blowjobs, haven't you?"
Feeling himself blushing and not trusting himself to speak, Robert nodded his head, prompting the man to tell him "Well, congratulations, kid; now you're gonna find out what they're all about."
Hearing that, Vic started to take a step and say something, but before he could finish either, the pistol was pointed his direction, and the man holding it demanded "You got something to say, asshole? 'Cause unless you're gonna tell us where to find what we're after, you best hold still and not make a fucking noise, got it?"
Quashing the desire to do or say something he knew was not only futile but would likely get him or one of his family hurt, Vic silently resumed his previous position. Still, there was no mistaking his anger and outrage as he listened to their masked master tell his son "To eat pussy good, you gotta wanna make the girl feel as good as she does for you. So you get into the right frame of mind, missy's gonna give you a blowjob first."
Carla turned her head to face the man, plainly surprised and disbelieving what she'd just heard. She was still looking at him when he told her "That's right, missy-you're gonna take your brother's dick between those pretty lips of yours and suck him off. You're gonna make him cum in your mouth, and you better swallow every drop of it, too… or else I might be tempted to think that you don't like his dick, and shoot it off. Got it?"
Terrified at the idea of Robert getting shot at all, never mind there, Carla softly answered "I understand."
Even hearing the threat of having it shot off his body wasn't enough to make Robert's cock flag even a little bit; the idea of having his hard penis in something other than his own hand was simply too much.
Standing there, he watched as Carla turned to face him before slowly sinking to her knees. A few seconds passed before she reached out and hesitantly cupped one hand under his scrotum while the other took tenuous hold of the base of his member. Doubting that anyone else could see, Robert could feel his sister slightly hefting his balls in her hand as though trying to guess their weight before she carefully (and gently, much to his relief) explored their size and shape. Apparently satisfied with what she learned, she turned her attention to performing a similar exam of his hard cock. When she was done, she leaned forward and gave the head of his manhood a tentative lick; a moment after that, she opened her mouth and took him between her lips.
Although she wasn't happy about what she'd been told to do, Carla wasn't what anyone could call disappointed about it, either: she'd been wondering what a real adult penis looked like, and although her brother wasn't quite an adult yet, he was certainly big enough-both in age and physical development. When she knelt down in front of him, she was getting an opportunity that she'd only dreamed about before then. Not daring to delay too long, she still took a few seconds to really LOOK at Robert's hard penis, it being both the first she'd ever been that close to and the first erection she'd seen.
Despite the circumstances, she couldn't help but feel a little thrilled by what she saw; after she got her hands on him, that thrill got even stronger. Raising the hand under his sack, she felt a mild surprise at how light it seemed in comparison to how big it looked; her tactile exam of its contents told her that his balls were generally shaped like the drawings she'd been shown in the Sex Ed class she'd had. Despite the gentle grip she had on his cock, she could still tell that it was incredibly hard underneath the smooth skin she was touching. Slightly awed by the size of it (her hand barely wrapped around it, and its width didn't extend even halfway down the length of it), she was amazed to realize that she wasn't afraid of the idea of something that big being inside her… knowing that a baby came out of the same place reassured her that the seeming monster she held would go in even easier.
Knowing what she had to do, Carla leaned forward and took a hesitant taste so she could prepare herself for actually having it in her mouth. Relieved to find that it didn't have any appreciable flavor, she did what she knew she had to and simply opened her mouth and took in what she could comfortably fit. She'd heard older girls talking amongst themselves, and read and heard enough other things to understand that "blowjob" was a misnomer; remembering what she'd already learned, she began putting it into practice and applied a gentle suction to the shaft that extended between her soft lips. With her hand still gripping the base of Robert's erection, she was able to keep him from thrusting himself even farther into her mouth-something that told her she was getting things right. As she continued to recall different bits of conversation she'd overheard, she began applying the details from them: using her tongue at different places and in different ways on her brother's manhood, changing the gentle suction she was applying in different ways, and even starting to slowly bob her head on him.
Having his sister's warm, wet mouth surrounding half his dick had left Robert stunned at how good it felt. When she'd started to suck on him, the desire to feel even more of the sensation was more than he could deal with; it was only the realization that it was Carla's hand around the base of his cock holding him back kept him from trying harder to stuff himself into the delightful confines of her mouth. Then when she started doing things to him, too… he knew that there wasn't a damn thing he could do to keep from climaxing in her mouth; all he could do was try to put it off for as long as possible. That met with only marginal success, and when she started moving her head on him in addition to everything else it was simply too much for him to bear. He knew she couldn't have shifted her head back and forth a dozen times before he felt his balls start to pull up; a couple more times of her lips sliding up and down his shaft, and he erupted.