I think the answer to the original poster's question lies in your answer. If you have to resort to having another guy yank you off, you are probably masturbating too much.
And this is where the thread twisted into that good ole' fashion clutchfans thread that we've all come to love.
No, but too much p*rn can be bad. If you need one to do the other, then look towards the cause of the problem and not the symptom.