In A Cup, As To Not Overwhelm Her

You watched as your younger sister's cheeks turned flushed, Jen seemed next to terrified for what was to come. "Jen? Hey, talk to me here, what are you thinking?" You gently asked while resting a hand on her shoulder,

Her big green eyes welled up once again while her lower lip trembled, "J-John...I-I...you're my brother, you're all I have but...it's your cum. I feel so fucking sick for asking for this, and now my head keeps making me think these horrible, disgusting things!" She cried out as you quickly pulled her into a hug,

"Jen, you need to listen to me, you have nothing to be ashamed of when it comes to this. You and everyone else who has this problem go through the same things, but it's your bodies way of saving itself. You need to seek out seman, the proteins inside it help counteract the disease, and you need it to be fresh. I can't imagine what's going through your head, but know I don't judge you at all," You reassured your younger sibling while slowly rubbing her back up and down,

"Are you sure?" Jen sniffled back, "I-I just didn't know who else to turn to..."

"So you came to your big brother," You smiled while pulling away from the hug, "No shame in that, you know I'll always do whatever it takes to keep you safe,"

"Even letting me drink your...you know," Jen nervously mumbled as she looked down at the ground.

Your eyebrow jumped up ever so slightly, merely hearing Jen say that made your cock start to stir. You were always a little embarrassed over the fact that you crushed on your baby sister, ever since she was sixteen and her body started to develop; you couldn't keep your eyes off her. It didn't help when you had family parties around the pool, and she'd walk around in the skimpy bikini's, or when she hit a phase in high school where she started showing off a lot of skin. You couldn't even count the number of times you came to the thought of her swallowing your load...needless to say; you were more than willing.

As Jen looked back up at you, you let out an easy smile, "Jen, I am your big brother, I'd give you my fucking house if it meant you'd be safe, and alive. So, yes, I will assist you, so you hold on to your self-respect, and once my team, and I develop a cure for this disease, you'll get the first dose."

Jen's plush lips finally parted into a genuine smile, and she quickly wiped her eyes, "Thanks, John, thank you so much..."

"No problem," He warmly replied as you watched her eyes slowly drift down your body, her green eyes turning from sad you lustful as she gazed at your crotch, "Jen," You softly called out as she licked her lips before nibbling on her bottom lip, "Jen," You called out a little louder,

"Huh?" Jen hummed back while snapping back up and blinking quickly, "Oh...I'm sorry, I just...my mind is making me think a lot of weird stuff right now,"

"Right, right, your dose, of course," You nodded while turning around and walking into your kitchen, Jen quickly followed you inside and watched as you went to one of your cabins and dug around,

"What are you looking for?" Jen curiously asked with a tilt of her head,

"I am looking for...ah!" You exclaimed while turning around, "This," You finished while presenting a thermos, "I'll use to top, that way you don't need to...see and become anymore uncomfortable with this,"

Jen's face dropped into a look of sadness, "I won't see..." She pouted before shaking her head, "Ugh! John, please, do it quickly, I can't take this!" She finally exclaimed in a pleading voice,

"Right, of course, Jen," You nodded while stepping back her once again, though your sister didn't seem to want to get out of the way anymore, rather she you to bump into her, letting your bulge brush up against her. She immediately followed you out of the den, up the hall and right to the bathroom door, "Jen," You chuckled, "The point is so you don't have to see, stay here, okay?"

Jen let out a small wince, biting at the inside of her cheek making her perfectly tan cheek bow in, before giving you a nod. You slipped into the bathroom, and immediately let out a husky breath as you nearly tore your belt off. Your cock was already about to burst; you were about to cum for you sister! She was going to drink your fucking spunk! You felt a small amount of shame, treating this situation as a gift, but your cock didn't care in the slightest, as far as you're throbbing shaft was concerned, this was a dream come true.

You pushed your pants to the floor and pulled your cock from your briefs; you placed the thermos cup right under your tip, which allowed it to catch the thick drooling stream of precum that leaked from your slit. Once you had it positioned to catch any streams that could possibly fire out too high, you wrapped your free hand around your shaft and started to pump. Your heart was beating hard, your legs were shaking, it felt like you were doing the dirtiest, most vile and taboo thing ever, but in reality, it was almost moral!

You only got a few quick pumps in before you heard a rapid tapping at the door, "You done? Did you finish yet? Need help? I can help, John," Jen's muffled voice rapidly asked, before nearly begging you to let her in,

Your head dropped back, you let out a breathy laugh, hearing Jen beg to help you cum almost instantly finished you. "I got it, Jen," You groaned back just before you shot a long, thick stream right into the cup. You made sure to moan out long and loud for your sister; you just couldn't resist. Stream after stream, shot after shot, continued to fill the small cup. Part of becoming a donor was producing as much cum as humanly possible; they only picked men who already had a high sperm count, then they put them on pills that would only further increase the amount. Having only just become a donor, this was your first load in about a weak, and with the extra production, the orgasm was mindblowing.

It took a long minute of you grunting and stroking your meaty shaft before you finally felt your orgasm pass, but when you looked at the cup, your eyes nearly bugged out. The cup was over halfway filled with your pearly white spunk, you knew, hands down, that you had never cum more in your life. You carefully placed the cup on the counter and fixed you pants before turning and opening the door.

As you opened it up, Jen nearly stumbled into you, clearly, she had her ear pressed to the door the whole time, "Where is it!? Where's your cum, John?!" Jen asked with a set of wide, hungry eyes,

"Here, this should be more than enough to set you straight, Jen," You replied while picking up the black thermos top, handing it over to your sister. Jen snatched it from your hand and brought it up to her lips, she took a deep inhale, sighing as if she smelled a nice cup of coffee before opening her mouth, throwing both the cup and her head back. You watched as your spunk poured right into Jen's mouth, and flew down her gullet without a moment of hesitation.

You simply crossed your arms and stood wide-eyed, loving the sight more than you ever thought possible. You noticed a small stream leaking from the corner of Jen's mouth, but as she finished with the cup, her fingers flew up, gathering up your cum, and pushing it back into her mouth. Your lips parted ever so slightly, and you let out a small exhale while your cock already started to stir. Jen looked down at the thermos and stuck her fingers inside it, swirling them around, gathering what was left onto her fingers before sucking them clean.

Then, as soon as the container was spotless, Jen dropped it on the floor and let out a long groaning sigh, "Oh my god...thank you, John!" Your sister exclaimed with a sigh of relief, "That was perfect,"

"Yeah? Feel better?" You asked with a little chuckle,

"So much better," She hummed back, "I can't believe how much you were able to...give too, that was...exactly what I needed. I'm already feeling better,"

"That's good, that means you're at least reacting to treatment," You calmly replied while reaching down and picking up the cup, "We usually recommend you get a dose once or twice a day," Jen's cheeks turned a little red, and she nibbled on her lower lip again, "What is it?"

"Are you going to be able to do that for me?" Jen nervously asked,

"Jen, I'm a doner, I'm able to give up to five or six fulfilling loads a day. Trust me, I can support you as long as you need," You smiled back,

"Oh thank god!" Jen exclaimed while rushing over to embrace you, "Thank you, John, you're the best big brother ever!" She nearly cried into your shoulder. You wrapped your arms around Jen and smiled; you knew that right now, she was by far the best little sister ever.