Cancer

A boundary that gets tested repeatedly is usually one that was set too softly the first time, with explanations instead of clarity. The testing happens because you left room for negotiation where none was meant to exist. When someone pushes against what you have said no to, they are not misunderstanding your position. They are checking whether your no has weight behind it or whether it was an opening offer. The boundary that holds is the one that requires no defense, only repetition. You do not owe anyone the reasons that make your limits reasonable to them.