Pisces men simply know how to please women. Because of their intuition and ability to read women ( The fish, is, after all, an emotional sign), they simply find it easier than most other men ( 'cept maybe for Libra men) to tape into women's needs.
Sadly, because the fish also turns in the other direction, they sometimes get into an emotional turmoil about how they feel about a particular woman. So they jump to another woman. This earns them the title of "cheaters".
I think the best sign for Fish men is a strong sign that will put them in their place & yet understand their deep emotions. Say a Scorpio or a Capricorn woman. I must add, though, the Capricorn woman will be harder to catch. The Scorpio will be a more viable choice.