What is the ruling on a husband having sexual intercourse with his wife during the daytime in Ramadan after a two-year absence?

If a fasting person intentionally engages in sexual intercourse during the daytime in Ramadan, he has committed a grave sin, and he must repent and seek forgiveness. The major expiation (kaffarah kubra) is incumbent upon him, in sequential order: freeing a slave; if he cannot find one, then fasting for two consecutive months; if he is unable to do that, then feeding sixty poor people.