Is what occurred between the suitor and his fiancée, including kissing and touching on an exposed rooftop, considered a valid Islamic seclusion (khalwa shar'iyya)? And does divorce take effect if the husband pronounces it three times, but the wife does not hear it directly, rendering her second marriage null and forbidden?

The criterion for a valid seclusion (khalwa shar'iyya) is that the spouses are alone in a place where sexual intercourse is possible. This valid seclusion entails certain rulings, including the obligation of the waiting period (iddah), which begins from the date of the divorce or the judge's decree thereof. It is not permissible for the woman to marry before the iddah concludes; otherwise, the marriage is invalid. We are not aware of how the husband pronounced the divorce, so it is advisable to consult a scholar directly to clarify the true nature of what occurred. The wife's hearing of the divorce pronouncement is not a prerequisite for the divorce to take effect; rather, its establishment through acknowledgment or clear evidence suffices.