Estoppel by acquiescence

Okay kiddo, imagine you and your sister both want the last piece of cake. You both argue and fuss over it for a while, but then your sister says "Okay fine, you can have it." You happily take the cake.

Later, when you're eating the cake, your sister can't suddenly change her mind and demand that you share it. She gave up her right to the cake by letting you have it, and it wouldn't be fair to take it back now.

That's kind of like how estoppel by acquiescence works. When someone says or does something that implies they won't argue about a certain issue or won't enforce their rights, they can't just change their mind later on and do the opposite. This is because the other person may have relied on their acquiescence and changed their behavior or position accordingly.

So, if someone says they don't mind if you use their land to pass through, but later claims you're trespassing, they can't really enforce this because they already let you use it before. This is called estoppel by acquiescence. It means that people can't just change their minds after saying or doing something that suggests otherwise, because it wouldn't be fair to the other person who relied on that representation.