trust - Trust is one of the most important and precious aspect of one relation in my opinion.The strength of the little piece effects the whole relation no matter how old it is.this little things breaks it with in a blink of eye and this same little thing makes up your relation.not only makes up your relation it also binds your relation up in other words glue your relation tight.so if you really want to keep up your relation never break trust as it is the only joining power between a relation.