it disturbs me that so many women feel threatened by masturbation and i'm equally disturbed that men don't have a problem with someone placing unfair demands on their personal sex life. your body is yours and your orgasms are yours and i think anyone with a healthy view of human sexuality should understand that. masterbation improves ones sex life; it is nothing to be jealous of and it should never be used as a way to control your partner.
(for my own part i'm single right now but all of my previous boyfriends haven't had a problem with my masturbating -- clearly i wouldn't tolerate such foolishness
).