CP ghost weasel.
Knowing the beginning of the end, for the companions who are separated.
They knew the outcome from the start. It was clear from the beginning that no amount of deep emotion could bind them to each other. Itachi's ending was planned by himself from the beginning. He could not and was unwilling to leave this ending.
Compared with the love that passes by unintentionally, this kind of love that knows it cannot be done, is willing to give even though it knows that the ending will be pain, and is willing to give its best at this moment even if it knows that there will only be unbearable feelings in the years to come. This kind of love is more in line with the tone of Itachi and Kisame's CP.
Destiny is the same as happiness. Acceptance requires more courage than resistance.