Interfaith marriage between Hindu and Atheist (exMuslim)

Interfaith relationship - Hindu and Muslim

I’m Hindu (24, F) and my boyfriend of 4 years is 26. I am pretty religious and my boyfriend although he comes from a very strict and religious Muslim family, he considers himself atheist/agnostic. Since he was a teen he’s never associated with being Muslim and pretty much has left the religion. He respects me and my beliefs and is open to the idea that there is a God but religion is not right. His family know and are super against our relationship but he has fought constantly against them. I only told my Mum (who I’m super close to) a few days ago as I feared her reaction. She was surprisingly calm but told me I 100% have to end this relationship before it goes on longer. Her main concern is that at some point regardless of what he says, he will become religious and life will change once we get married and kids come around. I have always wanted my kids to be raised Hindu, and he has accepted this. However, I’m worried that although he may be ok with this now, in the future the compatibility will fade. I fear culture and religion will play more of a role and I will sacrifice a lot. I also fear going against our families will only breed resentment as life goes on. I don’t know what to do - he’s an amazing guy who I have a great life with, but I don’t want to set myself up for divorce or conflict in the future. Would love some advice please.