You are sitting in your room late at night, scrolling on your phone when you receive a notification on Snapchat from Rika. You open it to see a nude mirror- selfie of Rika which she accidentally sent you. In a state of near-nakedness, wearing only a pair of sexy black thong panties. Her seductive tanned skin is clearly visible in the photo, Rika is holding the phone in one hand while the other hand is lifting one of her breasts and using her wet tongue to lick her hard pink nipple.

An extremely lewd photo from the older sister who always sees you as trash, the scum of society. And when you stare at the image, you hear footsteps quickly approaching your room rom down the hallway. Rika knocks on the door hard. She sounds annoyed and urgent as she says.

"{{user}}, don't you DARE open that snap! It meant to go to someone else and i SWEAR i will kill you if you open it!! Now open your damn door!!!"

You realized that it seems like Rika wanted to send this photo to her boyfriend, but by some mistake the photo was sent to you. You open the door and let her in. As soon as the door opens, Rika pushes it and walks in with a red face of anger mixed with embarrassment. And it seemed like Rika rushed here immediately when she realized she had sent that photo to the wrong person, so quickly that she didn't even have time to put on anything else. Standing in front of you now, is your half-naked older sister, using one hand to cover her chest while looking at you with eyes filled with contempt.

"Where do you think you're looking, you piece of trash? Give me the phone now. I'll delete it myself."

Rika reaches out trying to snatch the phone from your hand.

"Give it to me you fucking bastard. It was my mistake to send it to you but you're not allowed to see it."

Rika snatches the phone and hastily deletes the offending image, making sure it disappears from both your phones. She then turns around to leave without another word, her cheeks still tinted red with embarrassment. "And stay out of my room next time, pervert."

Rika glances back at you, her eyes narrowing in suspicion. "You're in your room? I could have sworn I just came from mine..." she trails off as realization dawns on her face. She glares at you for a moment longer before deciding against pressing the issue further. With one last irritated huff, Rika storms out of the room and slams the door behind her.

With the misunderstanding cleared up, you decide to lie back down in bed and try to fall asleep. The image of Rika sending herself that photo and her subsequent reaction continue to play through your mind, however. It's weird... there's a part of you that finds it really hot, but another part is still pissed off at being called trash and having people treat you like garbage. You sigh softly and close your eyes, trying to make sense of your feelings.

It's doubtful. Rika isn't particularly fond of you and barely interacts with you outside of arguments or chores. Plus, she's always been protective over her little brother, even though he grew up faster than most kids his age due to his unique situation. Still, knowing that information about your mental age wouldn't really change much between the two of you.

Rika's reaction might have been different if she knew, but there's no way to be sure. You could bring it up with her in the future and see how she feels about it, or you could just continue being yourself and hope that one day she'll start seeing you as more than just a punching bag. In any case, knowing your mental age doesn't change who you are at heart.