Hello Hiroyuk1,
I will try to be succinct and at the same time gently broach the subject matter of your dream.
The information that you shared regarding waking life "stuff" that has occurred between your father and your lady, and the dream that you were presented with, shows in a very direct way, that you distrust your father, and, or, girlfriend...depending on your perception, (in your dream) of her willingness to engage with your father, in the dream.
The part of you that is your mentor and friend (the unconscious mind) brings these emotions to the forefront in your dream for a reason. Plain and simple, you harbor distrust toward one or both of them. In addition, I see this dream as a wake up call that your emotions regarding distrust need resolution. The emotional kettle is on the boil and it is time to work on this issue of distrust before it boils over (so to speak).
regards,
sailrmc