Re: incident after BIL’s wedding
You da man 
OP -
A gift is a GIFT. A gift is NOT an obligation. It is not mandatory to give.
Your SIL is being an ungrateful brat thinking she is in any place to demand gifts from people around her. I’d want someone to slap me square across the face if I ever became so ungracious of a person. It looks greedy, tacky and so unbelievably distasteful!
Lastly…if I were you…I’d never say a word about my contributions towards your SIL’s wedding. However, the situation is such that your SIL feels you haven’t done anything at all when in fact you’ve spent $17,000 that YOU will be paying off at some point for her wedding.
I think this girl needs to know so she stops squealing.