That is a huge challenge. How was your relationship with your nephew before? did you approve of the union or disaaprove? Is his wife non-White? did he not invite you to the wedding because destination weddings are too fucking expensive? Do you have feelings for your nephew that are positived? Have you talked you to your nephew about why he didn't invite you to his wedding? In your experience does you nephew think things out or is he impulsive? Is your nephew under 25? Do you want to cut him off/out forever? Do you support his marriage? Is there an open bar at his reception. I've got, at least, another 70 questions. But the end question is: do you want to have a relationship with your nephew in the future and also, would going to the reception be a financial hardship upon you?