With a消极 attitude, he deeply understands that a lover is not a personal possession, and therefore cannot be possessed exclusively. He values the most genuine feelings of the present moment more than past memories or future promises with his lover. The relationship between him and you doesn't need further "stimulation" to deepen...
Note: There seems to be a typo in the original Chinese text with "<；p>；" which should likely be "". I've corrected it in the translation.