http://en.wikipedia.org/wiki/GandhiQUOTE
He felt it his personal obligation to remain celebate so that he could learn to love, rather than lust. Part of this may have been influenced by the fact that his father passed away while he was making love to his wife.
QUOTE
At the age of 13 Gandhi married Kasturba Makharji, who was the same age as he. They had four sons: Harilal Gandhi, born in 1888; Manilal Gandhi, born in 1892; Ramdas Gandhi, born in 1897; and Devdas Gandhi, born in 1900.