Curious to know if people are okay with uninvited guests?
Are you more accepting if it's a blood related family member? What if its inlaws?
What if they just turn up with no warning beforehand? How much warning is needed? Is it still annoying if they announce they will be visiting you on a certain day without checking if its okay first? Does it depend on how long they stay? Does it depend on what time of day it is? Where is the line for you from acceptable to annoying or cheeky?