LDS publication for bishops states that masturbation is almost universal for homosexuals and is a difficult habit to overcome.
Homosexuality, 2nd ed. (Salt Lake City: Church of Jesus Christ of Latter-day Saints, 1981), 2, 6
Early masturbation experiences introduce the individual to sexual thoughts which may become habit-forming and reinforcing to homosexual interests.
. . .
Masturbation is a sin, but is not homosexuality when practiced alone. When individuals of the same sex masturbate each other, it is a homosexual act. Self-masturbation is almost universal among those who engage in homosexual behavior, and is a very difficult habit for most to overcome. The fantasies that attend this behavior are often the most powerful aspects of the act.