Play your games. Wait an appropriate amount of time and then when you are in privacy with your sister, apologize. Tell her you are sorry for invading her privacy and you shouldn’t have pranked her like that. Tell her, sincerely, that you will respect her privacy going forwards and make every effort to be more thoughtful in your actions.
If she brings up the porn tell her you did not see what she was watching but that her healthy self expression is not your business.
If appropriate some light hearted humor in the moment about the awkwardness of the situation might lighten the mood and put you both at ease.
Going forward keep your your word and respect Hers and others privacy.
Act more deliberately and remember that pranks can be fun but they are also potentially dangerous and usually pointless. When you startle a person in certain situations they can hurt themselves or hurt you. This is made worse when the prank is “blind” and you have no way of knowing.
Reflect on that fact and think about what would have happened if your sister was cleaning her ears or putting on eye makeup or doing crafts with a blade etc. and had stabbed herself. If she were climbing to hang wall decorations and fell and broke bones or hit her head. Reflect on the fact that she or someone else if startled might hurt you. You could be shot while pulling scare pranks, a scared person might attack you with bare hands or whatever object they are holding. People have literally been killed by a single punch or slap. The odds are relatively low but it happens and would that prank have been worth it? Is it worth having to have seen your sibling masturbating? Neither of you needed to have that unpleasant moment.
No one needs to be hurt or killed either. A spilled drink or spilled paint or dye, a ruined project, a broken heirloom or personal item- there are lots of things that can go wrong especially when you burst in “blind” of what is going on behind “closed doors.”
Even if you don’t care or dismiss these things it is just simple manners to knock or announce/request before entering someone personal space like that, both out of respect and out of prudence because as you know first hand- we never know what is going on behind closed doors.
So overall in a general sense- “what do I do?” Use this as a growth opportunity and be thankful that the situation wasn’t worse, then move on with your life.
If she brings up the porn tell her you did not see what she was watching but that her healthy self expression is not your business.
If appropriate some light hearted humor in the moment about the awkwardness of the situation might lighten the mood and put you both at ease.
Going forward keep your your word and respect Hers and others privacy.
Act more deliberately and remember that pranks can be fun but they are also potentially dangerous and usually pointless. When you startle a person in certain situations they can hurt themselves or hurt you. This is made worse when the prank is “blind” and you have no way of knowing.
Even if you don’t care or dismiss these things it is just simple manners to knock or announce/request before entering someone personal space like that, both out of respect and out of prudence because as you know first hand- we never know what is going on behind closed doors.