I snoop on my wife's phone and laptop and now her sister's too
Why do you think that you should be allowed to go through their things?
I was curious about them because of the things they write in their emails.
It's completely inappropriate to snoop on your wife and sister-in-law's phones and laptops. People expect a certain level of privacy, and by looking at their personal devices, you're violating that privacy.
I can do whatever I want, they have to do the same. It's not like they are doing anything important.
I think that it is wrong to invade their privacy! How would you feel if your wife and her sister started going through stuff like that.