My boyfriend said, "I'll spoil you forever, but I won't spoil you. What does it mean?

Spoiled you, on behalf of love you, love you. But to spoil you means to indulge you, to do everything right or wrong as you please. He means that he loves you, but will not turn love into harm. Just like parents treat their children, excessive doting becomes harmful to the child, so your boyfriend thinks that love should also grasp the proportion, I believe he will be very good to you. I wish you happiness!