This sentence usually appears in romance novels or romance movies, indicating that the male protagonist has a strong possessiveness and desire to control the female protagonist, thinking that the female protagonist can only belong to him alone. The deeper meaning of this sentence might be the love and commitment of the male protagonist to the female protagonist. He hoped that the female protagonist would always belong to him and he was willing to pay any price for it. However, this sentence could also be a fictional romantic confession and not something that really happened.