Okay guys, I need some advice from people who might have experience with this kind of situation. So here's the nitty gritty: I've been NC with my NDad for 8 months or so now (yay!). Both my mom and sisters still talk to him. My mom kinda has too since she's going through divorce proceedings and both my sisters choose to. Also for context, he has a lot of money which he inherited from his father, which has essentially allowed him to be an increasingly lazy drunk asshole for the last ten years or so.

Anyways, Christmas. Two fat checks come in the mail for my boyfriend and I from my NDad. The choice is easy for my sister. She cashes it and writes him a nice thank-you email, which he apparently berates her about later. The way I see it is that we have three choices:

1. Refuse the money and continue NC- It's a good chunk of cash, but we're not broke and we both have full time jobs. We wouldn't be able to do something like go to Disneyland, but we're comfortable. This would also hopefully send a clear message that I want nothing to do with him. This is probably the most morally correct choice.
2. Cash the checks and continue NC- Yay money! But, he'll probably be pissed off and I'll burn that bridge, but in a different, less clean way. Kinda morally ambiguous.
3. Cash the checks and write a thank you card- This would be the most difficult choice for me to make in the current moment, but appeasing him just a tiny bit now might mean the possibility of a chunk of that inheritance when he dies. But is this a slippery slope? Will he expect more now that I've taken his offering?

I don't know what to do! Help!