Is expiation required for someone who continued to derive pleasure from a wet dream, leading to the emission of semen during a Ramadan day, and is this act considered masturbation?

Nocturnal emission ( احتلام ) during the day in Ramadan does not affect the validity of the fast, even if it leads to the emission of semen, because a person cannot avoid it. As for the emission of semen through thought ( بالفكر ), it does not invalidate the fast nor does it necessitate expiation ( kaffarah ) according to the majority of scholars, in contrast to the Malikis who hold that both a make-up fast ( qada' ) and expiation are obligatory if it is due to continuous lustful thoughts. However, if she was unaware of the prohibition, she is only required to make up the fast. And if it was his habit to be safe from semen emission during prolonged thought but he emitted semen, he is only required to make up the fast, without expiation. The obligation of expiation according to the Malikis is conditional on not being ignorant.