In their case I think it is/was their sexual prowess that held those relationships together. Obviously, most of the local Chinese men could not compete with them in regard to bedroom sports!

So true... This has nothing do with size either. Not smoking like a chimney, actually making an effort with foreplay and not suffering from premature ejaculation doesn't half help. Then again Chinese lads often never learn how to tread water due to having shared dormitories from school days onwards. But being selfish and blowing their cookies in less than 5 minutes doesn't help either.