I promised Moriah that I would elaborate on my thoughts about masturbation and sin. This message regards masturbation in a heterosexual marriage. It can either involve self masturbation or masturbation of your husband or wife. The reason I am addressing one group at a time is because any replies using different groups could be confusing. I hope that I do not exceed our morality rules by this post. If so, I pray that someone tells me or a mod picks it up and deletes it. My commentary follows.
Mirriam-Webster Online Dictionary defines masturbation as erotic stimulation especially of one's own genital organs commonly resulting in [bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse][bless and do not curse] and achieved by manual or other bodily contact exclusive of sexual intercourse, by instrumental manipulation, occasionally by sexual fantasies, or by various combinations of these agencies.
Personally I believe that masturbation in a heterosexual relationship can be normal, healthy and pleasurable. From a psychological point of view, masturbation is only harmful if it interferes with, detracts from, or becomes a substitute for intercourse.
However, masturbation can become sinful. If a marriage partner fantasizes about anyone besides the person he or she is married to during masturbation then I believe they have committed the sin of adultery as Jesus expanded the definition below in the book of Matthew.
Matt 5:28 But I tell you that anyone who looks at a woman lustfully has already committed adultery with her in his heart.
It is logical to deduce that fantasizing about another person than one's marital partner is another way of 'looking at them' so I think that the above scripture applies. And as both Old and New Testament law states, adultery is sin and we are not to partake of it.
An interesting, expanded commentary is given by Jamieson, Fausset & Brown. They state, "We are not to suppose, from the word here used - "adultery" - that our Lord means to restrict the breach of this commandment to married persons, or to criminal sexual intercourse with such. The expressions, "whosoever looketh," and "looketh upon a woman," seem clearly to extend the range of this commandment to all forms of impurity, and the counsels which follow-as they most certainly were intended for all, whether married or unmarried-seem to confirm this..."
God bless,