How about a quick test?

You blink back to reality, the touch of her hand returning you to your senses for a moment. The glasses are still piping information to you, and the movement prediction seems to be on point but you really can't just assume the rest of it is accurate, can you?

"Huh? Oh, yeah. Sorry. I'm fine..." You shake your head.

Zoe remains unconvinced, placing her hands on her hips and making a cute, disapproving expression.

Still, you can't help but see your sister in a new, incredibly sexy light. She's a total freak. And thanks to your glasses, you're pretty sure she masturbates to the thought of her big brother **** her. Not that you could even if you wanted to...

She picks up a towel she'd stashed by the door and your glasses warn you that her phone is about to fall out of its little carrying thing on her arm, so you reach out and catch it before it manages to fall even halfway to the floor.

Your inner ninja celebrates total victory over the laws of physics at such an incredible save. Zoe seems equally impressed as she reaches for her phone. "Wow! That was a great save! How did you do that?"

A bizarre blend of horny male brain, lewd details about your sister's fetishes, and a supreme sense of physical confidence leads you to do something that would have been absolutely unthinkable mere minutes earlier.

Unable to keep a grin from your lips, you say, "Hey Zoe. Think fast." It was a game you used to play as kids, back before Zoe's training had turned her into something approaching a living weapon. That, and well, you both became teenagers and wrestling became awkward.

As she reaches for her phone, you grab her outstretched wrist with your other hand, tossing the phone safely to a nearby couch to free up your first hand.

She brightens. "Oh, I thought you hated this game because I always win!"

But this time, when she moves to gently perform a move that could have broken your wrist, you see it coming and adapt, twisting her arm and sidestepping. You counter everything she tries, pulling on her balance and kicking her feet out from under her until, within a minute of beginning the game, she's on her knees with her back to you, both arms twisted up behind her back in your grip. She's completely unable to struggle without potential injury to her shoulders.

"What the fuck?" she curses, panting. "Have you been practicing? That was insane." She pulls gently against your grip. "Hey, okay, you win, you can let me go now..."

Your glasses indicate again that she's growing increasingly aroused.

"How about that." you say to yourself. "Well, I guess I do win. Well you know the rules, that means I get a prize."

In the past, that would often have meant dibs on the family computer, or control of the remote for a week, but really it could be anything.

"W-what sort of prize? And let me go already." Despite her words, her tone is much more agreeable and less angry than you'd have expected. Almost embarrassed.

Glasses indicate more heightened arousal, by now it's even detectable in her voice, but only because you're looking for it.