Aquarius.
Gemini male
The most compatible sign for Aries is Sagittarius. But Leo could do well in a relationship with them, too, not only Sagittarius.
Generally speaking a Sagittarius-Virgo relationship is difficult.
Sag female likes the silver tongue of the gem male.
A male Capricorn should marry a Capricorn, Taurus, Virgo, Cancer, Scorpio, or Pisces (all feminine signs), but if a Sagittarius or Aquarius has Mercury, Venus, or Mars in Capricorn, or if the Capricorn has those planets in Sagittarius or Aquarius, then marrying a Sagittarius or Aquarius would work too.
It Turns Them On
A Sagittarius woman should marry the man she loves. His sign will be totally irrelevant. So a Sagittarius woman can marry any of the 12 signs. Marry someone based on their personality, and remember that their personality is not defined by when they were born.
there are no male chanseys in pokemon diamond, perl, or platinum. get a ditto instead.
A male Kirlia
in wayward cave
You ask him. It should be about that easy, if he is a straight male.