Masturbation is one of those gray area's in the bible- it dosent really say a whole lot about it- or any really for that matter. The bible is very clear about keeping away from evil, and our minds and hearts pure. When it comes right down to it, sex was created for man and woman, for eachother, a deep, strong bond- pleasure and to create life. Masturbation is a selfish act. And Im not sure about you, but I dont know how one could be aroused, and touch at the thoughts of anything that isnt impure (think about it- can you be aroused, and touch while you are concentrating on your math homework? Doubt it) Even before you are married, having impure thoughts about your s/o is still considered a sin. YOU ARE NOT MARRIED TO THAT PERSON. And until you are married to taht person, any lustful or impure thought about that peson, whether you like it or not, is a sin.
Now do I think masturbation within marriage is wrong? Yes and no. Let me explain. If you are substituting masurbation for sex, meaning, if you are masturbating instead of having sex with your husband/wife, then yes its a sin, and it is depriving your husband/wife of the intimacy that God intends through Sex. So then what about when your wife is on her period? Or pregnate, or just not feeling well.... I still think you should restrain yourself from masturbation- I think its important for people to practice self control even when they are married.
Now- with your husband/wife... is it wrong? I dont think so. I dont see anything wrong with manually stimulating your husband/wife within the marrige bed together. But that would be a decision made between the couple. What goes for one couple, may not be the same for another couple. As far as I am concerned, anything respectable goes between a husband or wife (excluding bringing in another person, or watching porn etc) as long as they both agree, and no one is getting hurt.
Now to adress something in the OP- It sounded like you said something about manually masturbating someone, but not having sex. I think its very important that you understand that all sexyal activity is considered a sin outside of marriage. If you are awakening desires that should not be awaken before you are married, Im sorry to say but that would be considered lustin... which is a sin.