You'd never turn down a handjob

The rest of the day is strangely normal, with you playing video games on the couch while your sister makes an emergency run to the corner store for condoms, which she insisted on since the whole point of this arrangement is to cut down on "mess." In the back of your mind, part of you still thinks this is some elaborate joke, but you've decided to just play along and see how far she'll let this go.

"You better not have lied about your size, dude," she jokes when she comes back, sitting on the couch beside you and tossing the box of condoms into your lap. "I don't get why guys lie to people that they want to show their actual dicks to. Like, I'm going to see it. Touch it. I know what is and what isn't 6 inches."

You look at the box -- it's a value pack, suggesting that this will be a long-term thing.

"Nah, these are right," you nod. "So, uh, when were you planning on... using one?"

"Well, when do you usually jerk off?" she asks. "Is it a daily routine, or just whenever you get hard? I'm usually satisfied with one good session every week or two."

You blink, surprised by how casually she just disclosed her masturbation habits. The thought, and the whole situation, has you turned on already.

"Well, I'm hard right now," you admit. "I'd probably go rub one out soon. Are we going to my bedroom, or...?"

Your sister shrugs, stretching out on the couch. "I'm comfy right here. Wanna pull something up on the TV and stand in front of me so I can, like, reach around you?"

A few minutes later, somehow, you're standing there in the living room with your pants around your ankles and two lesbians scissoring on the wide screen TV in front of you. You usually just use your laptop or cell phone, so seeing these women almost life size is a whole new experience.

Another whole new experience is the hand reaching up between your legs, your balls resting against the wrist as it pumps a lube-filled condom along your shaft. You never knew a condom could feel this good, and the fact that it's someone else's hand -- you own sister's, no less -- adds a thrilling extra dimension to it all.

"Is that the right pace?" she asks. There's no arousal in her voice, but she does seem like she wants to make it feel good for you. "You're throbbing a little bit. That's good, right?"

"Yeah, it's good," you grunt. "Really good. Would you mind... not talking? It's still a little weird that it's... you..."

"It's just a hand, dude! You have one, too. Just focus on the video."

You do your best, watching the women's breasts jiggle and staring at the spreading strings of grool between their wet pussies. Before long, you can't help thrusting your hips against the stroking fist, closing your fist and throwing your head back.

"O-okay, slow down. I'm about to... to cum..."

"No way, dude! I'm not edging my fucking brother. Just get it over with already, so I can go wash my hands."

She keeps going at full speed, overstimulating your sensitive dick just a little bit as she pushes you over the edge, milking your balls into the rubber sleeve. She strokes through your whole orgasm, waiting until your stop groaning and grinding before slowly peeling the condom off.

"That's a good boy," she sigh sarcastically, tying the end of the condom and rushing off to the bathroom. You hear the toilet flush and the sink run, still standing there with you softening dick out as the porn stars on the screen in front of you have orgasms of their own.

"Okay, go take a shower or whatever," your sister says when she comes back. "You can cook me dinner tonight as a thank you."

She kisses your cheek, then flops down on the couch again and changes the TV to some gaming YouTuber instead.