If Pisces as a person is not interested in you, it would be that he is becoming grumpy, distant, and…
Pisces is the twelfth astrological sign in the Zodiac. It spans 330° to 360° of celestial longitude. Under the tropical zodiac the sun transits this area between February 19 and March 20, and under the sidereal zodiac, the sun transits this area between approximately March 13 and April 13. In classical interpretations, the symbol of the fish is derived from the ichthyocentaurs, who aided Aphrodite when she was born from the sea.
While the astrological sign Pisces per definition runs from elliptical longitude 330° to 0°, this position is now mostly covered by the constellation of Aquarius, due to the precession from when the constellation and the sign coincided. Today, the First Point of Aries, or the vernal equinox, is in the Pisces constellation. There are no prominent stars in the constellation, with the brightest stars being of only fourth magnitude. One star in the constellation, Alpha Piscium, is also known as Alrescha, which comes from the Arabic الرشآء al-rišā’, meaning “the well rope,”] or “the cord.” The constellation however is different from the astronomical location in where the sign occupies space. The constellations in earlier times were primarily used as markers to help determine what influence was in the sky. Nevertheless, the sign of pisces remain in the 30 degree span of 330°-0°. (link from wikipedia)