What is the expiation for someone who committed fornication with his fiancée during the daytime in Ramadan, and did not make up the days he broke his fast while traveling previously?

You have committed a grave transgression by intentionally breaking your fast during Ramadan and engaging in sexual intercourse therein. You must make up for that day with expiation (kaffarah): freeing a believing slave. If you cannot find one, then fasting for two consecutive months. If you are unable to do that, then feeding sixty needy persons (approximately one and a half kilograms for each needy person). This order is obligatory. It is more prudent for the wife to also make expiation, and the Hanbali school of thought obliges it upon the compliant woman. As for the days you broke your fast while traveling, you must make them up, and in addition to making them up, you must feed one needy person for each day due to delaying the make-up until the next Ramadan began, unless you were unaware of the prohibition of delaying.