I don't, your wording was just a bit generally vague to the subject so I had to draw some assumptions on what you were referring to (being in a thread about watching porn). ;p And no, I don't treat masturbation as harmful (thought I made that clear by now), but call me crazy for preferring sex to masturbating to porn and thinking that you don't have to find a way to blow your load every time you feel like having sex. (again, masturbation in the context of porn is very different, you're probably referring to it more generally)
As for the edit, I think it's naive to worry about exploring sex in a relationship because someone else might 'beat your to it'. A relationship isn't that simple, just found it funny to think that you viewed it as a craft that needs to be mastered, in that specific context.