麟媽媽,
Understand why u said 我是不是好小氣. I don't know how much your hubby asked for, but unless they are really very 手緊, I will definitely pay my share if I were them - afterall, she's their mum!!! Buying her a present is different from contributing to your household, maybe they should buy u two a present too! Is it possible that u all hold a family meeting to talk it out (at the absence of your in law)? It's better to air out all your concerns to make it even among the 3 brothers than to have sour feeling. Since your husband is the big brother, he should & has the right to do so.