That is quite a thought. I'd rather like to hear how those stories continue!I have masturbated in front of my partner or vice versa without the other person also masturbating.
However, I was going to say ... each of you masturbating for one another (as you originally mentioned, and as opposed to this, where one person shares just for the other to watch) is certainly one meaning of mutual masturbation.
However, it can also mean each of you masturbating the other at the same time. I thought this question probably referred to that, because it also had separate questions both about masturbating with your partner, and watching/being watched.