I don't see how you could keep it from them, but, a few years ago a woman held a winning ticket for some monrths, then gave it to her husband for Chrstmas, in a Christmas card or wrapped in a very small box, and said, "I'm sorry honey, this is the best I could do this year".
Have thought about this for a while, and it would go off in one of two ways:
1) Hire an attorney, create a blind trust, and have the trust claim the prize and receive the winnings anonymously. Then, once the cash hits the bank, fly in the in-laws into town on a private jet, without their full knowledge of what was going on, nor my wife having a clue. Then spring it on them at a great resturant in a private room.
2) Call the wife, and tell her to come down to the attorney's office, stating that I had received papers related to pending suit, and that she needs to come down to be part of the discussion concerning the defense. Then, when she arrives, spring it on her in a private conference room.
Either way, she will never work again.
In reflection, I think that I like the first method the best.
I am not married, but I do have a girlfriend and we had a son together! So on a legal standpoint, I don't have to say not one word to her about my winning the jackpot! Of course it would be claimed by a trust, then when the money hits the bank, most of it would be moved offshore. Oh just to let some of you know, the IRS does have agreements with some countries for them to tell them about US citizens with nice size bank accounts, so they can be taxed by the IRS! I'll make sure to use a bank offshore with no such agreement with the IRS!