Dear Amy: My wife “Mel” and I are newlyweds.

After the wedding, my wife’s grandfather sent her a check for $10,000.

I jokingly asked her to hand over my $5,000 share as her new “partner.”

She responded with an angry rebuke, which inspired me to start thinking seriously – why aren’t I entitled to share in this wedding gift?

– D

Dear D: This answer would depend on your wife’s grandfather’s statement of intent when he sent this money. Was this a “wedding gift,” or a gift sent to your wife after your wedding?

If the money came along with a note saying, “Mel, I hope you will use this gift toward retiring your college debt so you can get a running start to your marriage,” then the grandfather is using the occasion as a way to give his granddaughter a special gift.

If the grandfather did not state any specific intentions and addressed the card/envelope to both of you as a wedding gift, then it is for both of you.

In my opinion, you blew it when you jokingly asked your wife to hand over your half, although the real gift here is that this episode should force you two to discuss your finances: What’s hers, yours, and ours.

Being married should inspire both of you to change your orientation from “me” to “we.”

Will you deposit your paychecks into a joint account and pay your expenses from this account? Will you pay your expenses proportional to your incomes, or split them equally? Will you each assume responsibility for your own credit card debt and agree not to let the balances grow over a set amount?

Moving forward, if one of you wins the lottery or receives money from a family member, will you deposit it into your joint account to be shared equally?

If you two divorced, these matters would be decided by the community property laws in your state. During your marriage, you get to make these choices as a couple, and I hope you will.

A postnuptial agreement would codify some of these decisions, and is essentially a roadmap for dividing assets if you divorced. Even if you get a post-nup, don’t plan for your divorce; plan for your marriage.

You might ask your wife how she would react if the situation were reversed, and you had received a generous cash gift from a family member. Would she expect you to share the gift equally? (I expect she would.)

Would she thrust out her hand and immediately demand half? (I expect she would not.)

You can email Amy Dickinson at [email protected] or send a letter to Ask Amy, P.O. Box 194, Freeville, NY 13068.