Spiritual & 'Worldly' Pleasures If the mind experiences more and more happiness, calmness and all the other positive emotions due to virtue and meditation, does the mind then by itself slowly (!) withdraw from sensual pleasures?

Answers with sutta reference are preferred
The joy and happiness of spiritual development is considered to be far more superior than sensual pleasure, which is fleeting and bound up with suffering, as explained in MN 14. Also see SN 36.31 for further info.

Even though a disciple of the noble ones has clearly seen as it actually is with right discernment that sensuality is of much stress, much despair, &amp; greater drawbacks, still — if he has not attained a rapture &amp; pleasure apart from sensuality, apart from unskillful mental qualities, or something more peaceful than that[4] — he can be tempted by sensuality. But when he has clearly seen as it actually is with right discernment that sensuality is of much stress, much despair, &amp; greater drawbacks, and he has attained a rapture &amp; pleasure apart from sensuality, apart from unskillful mental qualities, or something more peaceful than that, he cannot be tempted by sensuality.