In the name of Allah, the most Beneficent, the most Merciful.
There are two types of shias:
- Those who believe that the Qur’an has been altered, Saaiduna Ali Radiallahu Anhu to be god, accusing Saaiduna Aaisha Radiallahu Anha of committing adultery etc.
Those shias who hold such views are out of the fold of Islam, thus such a marriage with a Shia will be invalid. (Raddul Muhtar p.135 v.4)
- Those who do not hold such beliefs, which constitute kufr, like believing that Saaiduna Ali Radiallahu Anhu was the rightful first caliph after the death of the Prophet of Allah Sallallahu Alahi Wasalam and not Saaiduna Abu Bakr Radiallahu Anhu. Marriage with this category of Shia should not be considered however; if it is done it will be valid. (Ibid)
With regards to your question as the marriage with that Shia whose views constitutes kufr, such a marriage will be considered invalid. In an invalid marriage there is no waiting period even though there may have been sexual intercourse. The sexual intercourse would be considered as adultery and waiting period is not necessary after adultery. (Fatawa Hindiyyahh p.526 v.1 & Fatawa Darul Uloom Deoband p.306 v.10)
If he repents and changes his beliefs then it will be permissible to marry him. However, one should try and deduce whether he is genuine in his beliefs or not as many Shias display outwardly not to have beiliefs which constitutes kufr but keep these beliefs in their heart which they call ‘Taqiyaa’.
Only Allah Knows Best
Mohammed Tosir Miah
Darul Ifta Birmingham