Is a person considered an apostate from Islam if they utter the majestic name "Allah" to themselves when watching pornography, and is simply uttering the Shahadatayn sufficient to return to Islam?

One who experiences a fleeting thought of disbelief (kufr) without intending it, believing it, speaking it, or acting upon it, does not become an unbeliever. Allah has forgiven this Ummah for what they merely think to themselves, as long as they do not act upon it or speak it. However, whoever intentionally and knowingly utters a word of disbelief with their tongue, or believes in disbelief in their heart, then they become an unbeliever thereby. The repentance of an unbeliever is accepted if its conditions are met, for "the one who repents from a sin is like one who has no sin." It is necessary to be wary of obsessive thoughts and to strive against one's self to abandon such ideas.