Families are like countries.

You have to understand one thing. Families are like countries, they have borders, some of them are theocracies, some are dictatorships, some are anarchic hullaballoos. Some have great cuisine, some are multiethnic, anything a country is, a family can be. With more power over the person who lives there than any country can ever have, I don't care what. So when you go with someone, to that person's family YOU are a foreigner. If you're a tourist, they will not pay you much mind and you'll get some souvenirs, and some photos for an album, that you may or may not burn at a later time. But if you're planning to apply for citizenship, you have to understand that there are rules, regs and all sorts of taxes. Ignore them, and you end up in exile, with or without your sweetie. Most families will recognize dual citizenship, which means things like they will understand splitting the holidays and giving equal time with the eventual grandchildren. But in some cases, you're expected to renounce your allegiance to your own family, or that your honey bun can have no real doings with yours. It's good to figure that out ahead of time, if you can. Some warning signs
1. All wedding and prom pictures of any of your sweetie's siblings exclude mates and dates.
2. Your sweetie attends the weekly barbecue, with or without you.
3. Your sweetie has to think about whether to attend your parents' 25th anniversary party or the dance recital of a second cousin's third grandchild, scheduled for the same day. Trouble!