In the name of Allah, the most Beneficent, the most Merciful.

Answer

As long as your father has given you permission to choose the partner of your choice, even though he does not know you have already married, the marriage will be deemed permissible and correct according to the teachings of Imam Abu Haneefah (RA).

Only Allah Knows Best

Mohammed Tosir Miah

Darul Ifta Birmingham.