all three of us siblings are "inter". My sister and i are inte- rac marriage and my bro is inter-cult marriage. good thing about us is that our dad always raised us to be open and practical. so our parents are always involved in every special event from all four "backgroud". my wife is from south america, my bro-in-law is from the carib-island, and my sis-in law is from nepal.
every special event/occasion are so much fun and a really good learning experience for all of us. We do feel some bad talks from the nepali community but they are from the older generation and my wife feels the same way from her side...all coming from the older generation.

Someone brought up the indian culture n how they are able to retain that. i think its because they have a bigger influence among the brown asian.

Long story short - you can raise your kids with all the intention of keeping the culture....but with each generation, the nepali culture will be more and more diluted and become more and more american. Just accept it, embrace it, and enjoy the time with the kids and know that your kids are more open and knowledgeable about world than most.