Do his parents need his money? Why? Are they elderly or infirm?
I just dont understand parents who take money from their married children. I'd go on welfare before I accepted money from my kids.
With all due respect, I find that a very shallow argument from the kids' perspective. If parents think that way, I think it is okay for them, but kids using the same argument as grounds for not supporting their parents, is the height of selfishness.
Moreover, west and east are quite different when it comes to social norms, familial bonds, nurturing of kids and the expectations from kids when they grow up. In the west, most parents think their job in terms of financial support is finished once the kids start college. In the east, given that the parents can afford it, the financial support isn't over with till much later, and especially when the social safety net (Government loans for studying, grants, bursaries, scholarships etc) is not even an iota of what exists in the West, children owe a lot to their parents for all their education and progression in career.
So if he was given support for his education, it's his moral duty to keep returning the favor, and even if he wasn't supported enough, they are his parents.