Purity: Permissibility of Foreplay During Ḥayḍ

Practical Laws of Islam as per the teachings of Ayatullah Sistani

Ruling 451:

Apart from having sexual intercourse with a ḥāʾiḍ, there is no problem in deriving other forms of sexual pleasure with her, such as kissing and foreplay.

-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)