It's no longer in the DSM as being something bad or wrong. You have a right to pleasure yourself, it's your body. Why do you have to see that as coming out? And maybe your wife simply can't see that you should be able to learn how to self satisfy. If you love her and she is not capable of engaging in sex, then you should at least be able to satisfy yourself. It's just physical and you are not looking for someone else in a relationship, you would just like to enjoy that one pleasure.

I think that other members are telling you that it's really ok for you to pleasure yourself privately. Most will admit they don't see it as wrong or bad or cheating.