Well, we live in a fallen world, we are all human, and while on this earth we will always be sinners. It is a part of life in this world that we will fail and hurt others and they in turn will fail and hurt us. That doesn’t mean that we are all terrible or that this life is not worth living, but it is just a recognition of the failings and hardships we will have to deal with here on earth.
Because of this, when we give oursselves completely to another while still in this world there is always a chance they will fail in some way that will hurt us and that we will hurt them. Please understand that that is not a reason to avoid deep and meaningful relationships here on earth, but rather if one is faced with great difficulties due to the failings of ones spouse one must then remember to turn to Christ on the cross for comfort and consolation, ask him to shoulder our burden for us, and rest assured that even with all the failings in this world, He loves us unfailingly, endlessly, perfectly, with the greatest love of all, the love that is God Himself.
So, no, the different persons of the trinity do not ever have to be afraid of something bad happening.
There are people here on earth who are certainly animated by this perfect divine love at least at times, but since they are still in this fallen world and state, they will still fall and sin, even the greatest saints recognized that they were still sinners.