If the Bible is the standard in your life, then masturbation is not sinful.
Onanism is another word for masturbation. But Onan didn't get into trouble for masturbating.
Onan's older brother died without producing a son. It fell upon his younger brother to produce a son for him. However, Onan wasn't married and didn't have any sons of his own -- and didn't want his own first-born son to legally belong to his older (and dead) brother. On the other hand, Onan had to trouble with fucking Tamar. However, he'd pull out and shoot his load on the ground.
In the end, Tamar tricked Judah (Onan's Dad) into fucking her by pretending to be a whore -- and, yeah, she got pregnant and had her son.
And that's the ONLY reference in the Bible to masturbation and it clearly has nothing whatever to do with masturbation.
And people think the Bible is boring.
I think it was Dr. James Dobson, who is kinda like a Christian Dr. Phil only with a bigger mouth, once said "Masturbation is probably the least of God's worries". There's nothing wrong with it until you get addicted. Then you have a problem! For men, our bodies self masturbates itself periodically to release old semen. This is the nocturnal or wet dream phenomenon. Nothing wrong with helping your body along at times.
I asked a question in another Christian group on here if anyone agreed that masturbation is major sin and I feel like I got ripped in what I said because I am giving up masturbation. So I will ask you all about the same thing, is masturbation a sin?
I dont believe it is sin either, in fact, when couples share it openly and intimatly in mutual masturbation it allows the partner to really get a good look at where the other is receiving pleasure.... We all respond to touch differently so this shared masturbation can truely open the door to heightened states of ecstatic pleasure for both partners.
It has been my experience, that different Women enjoy and prefer different styles of touch on there vulva and clit. So i say, use masturbation to really get to know your body and your pertners body... you will both reap the pleasure and orgasmic rewards from it.