Religion is probably the reason he has a problem telling them about you, and if that's the case, then it will be just as big a deal for his parents as it would be for very devout Catholic, Muslim, or Jewish parents. I've known Jehovah's Witnesses who mix with their non-religious relations at family celebrations, etc, but when it comes to relationships between their children and an 'outsider' it's an entirely different matter. In fact one Jewish friend of mine was, in effect, forced to give up her Catholic boyfriend because her father was quite prepared to disown her and never allow her to see any of her family again. I think your boyfriend is going to have to be very determined. Good luck. x