Masturbation?Sinful?!

Masturbation?Sinful?

I was wondering if I feel fine with masturbating, yet the church claims its a sin?

I don't feel bad when I do it? So is it a sin?

There is a story in scripture about a man who was killed because he did so rather than give his dead brother's wife a child. Many people misunderstand the message and claim that spilling his seed as he did was the sin when in fact it was his refusal to give the woman a child that was against God's will.