FOR MORMONS ONLY; is negativity towards masturbating more suggestive, or considered more like law?:?

My boyfriend and I have been discussing masturbation recently, and he is of the LDS religion... he has never masturbated before and this just blew my mind,. I thought everyone had done so, since the age of 11. I can't imagine not being curious and exploring your own body, So the purpose of the question is to find out, whether or not by his religion, is ill will towards masturbating more like a suggestion, or a law? we are both unsure.