I have been asked this question by a teen family friend.
He said 'Dad says I am a Muslim, am I?'
At the time of his birth
-his parents were unmarried (never married) but living together.
-Father self defined as Muslim (seemed to be non practicing in an outwardly visible sense, he may have converted I don't know, though was from a non-Muslim background himself prior).
-Mother was/is not religious or might define as a non practicing C o f E Christian.
-Child brought up by mum from toddlerhood with little input from dad until later teen years.
-Teen is not practicing any religion and hasn't to date.
If you can let me know how to find out the answer or indeed the answer and why it is such, it would be much appreciated.