Lets say one has a mixture of different foods and one wishes to select one to show to a child to see if they would like to eat it. One doesn’t know whether the child will end up deciding to eat it or refuse it. Would it be a problem of borer to select such a food to show to the child?
It is permitted since you are taking it because you want it, and it is for now. If the child will refuse it afterwards, it doesn’t take away from the fact that right now you wanted it because it is good.