Question: What is the ruling on someone who engaged in foreplay with his wife while fasting and ejaculated without intercourse? May Allaah reward you!
Answer: If a husband engages in foreplay with his wife while fasting during Ramadaan and ejaculates without intercourse, his fast will be invalid, and he should abstain from fast invalidators for the rest of the day. Moreover, he has to make up for that day (after Ramadaan) and ask Allaah for forgiveness.
Anyway, he is not liable for a Kaffaarah (expiation). So while fasting, we must guard our fasts against acts or words that nullify it or cause it to be defective. In this regard, a fasting person should abstain from sexual desire, eating, and drinking for the sake of Allaah as authentically narrated from the Prophet (peace be upon him)… read more here.