I watched in netflix a series called spartacus ,but with a lot of porn like sex scenes in it. So is this considered as an relapse?
No, unless you purposely watch the show for these scenes. Better to avoid it altogether in reboot, it might create cravings. It's not a relapse untill you deliberately watch it, going against your willpower. But if it is there by accident, like an advertisement in the streets, it doesnt reinforce anything. As a matter of fact. If it comes and you look away, it might strengthen your resolve a bit.
Note the difference between a reset and a relapse. A reset is when you reset your counter, because you deliberately watched porn, or because you masturbated. A relapse is the effect that it has on your brain, when your brain's healing is set backwards. This means that you can have a reset without a relapse, and (in rare cases) a relapse without a reset. What you did almost certainly isn't a relapse, because (given the circumstances) your brain almost certainly didn't go backwards in its healing. Also, I agree with @TheRIghtChoise that you don't need to consider it as a reset.
