Is Your Son or Daughter Getting Married?

2. A marriage doesn't have to be perfect to be good and long-lasting

When parents have stayed together and avoid arguing, kids may idealize their parents' marriage, and it's helpful for them to know that even the best marriages are complicated propositions with happy and unsettling events.

"Some couples talk about good and bad days," says David Treadway, Massachusetts couples therapist and author of Intimacy, Change and Other Therapeutic Mysteries. He and his wife married at 21 and 22, and they like to remind their sons, "We talk about good and bad decades. And our first decade was a bad one." But the Treadways are going strong four decades later, and Dad is proud that they've been honest about themselves with their sons. "They see our limits and our flaws as people and as a couple," he says, adding the message he wants his kids to take away: "You don't have to be perfect people to have a good relationship."

3. You can offer hope even if your marriage didn't last

If parents are divorced or single, they can still be genuinely optimistic about their grown kids' marriage plans and potential. What not to do can be the most useful kind of example. A parent can admit, "I wish I hadn't worked so much/drank so much/said those things" or "We would have been better off if we had compromised more/made more time for each other/been able to forgive each other." There's always a way to show the next generation that with awareness, kindness and patience they can make better choices than their parents did. The wedding itself is a good place to start. What could be a better gift than parents who are ex-partners being civil, even cordial, at the ceremony?

4. Get ready for give-and-take

As teenagers morph into emerging adults, conversations shape-shift as well, from what's for dinner to what matters in a life partner and how to weather the storms to make a marriage endure. Now parents need to be ready to answer some tough questions as well as dish them out. Think about how open you want to be about your life. Your kids might well ask you, "You've stayed married. Were there moments when you feared you would not?" Or, " You got divorced. Why?" Not everything has to be divulged, but there's room to negotiate what's too private on both sides while still keeping the lines open.

As your child stands at the altar, perhaps most important of all will be not what you say but how you make room in your life and your heart for the person your grown-up kid has chosen as a life partner. If you're lucky, that person will be just the person you would have chosen, too — but chances are better that your kid's soulmate will have more tattoos or fewer financial resources than you might prefer. Your ultimate challenge, and your ultimate act of love, will be to shower them both with all the love and support you can, and to accept without complaint the truth that comes to all parents as their kids become adults: It's their life to live.

Jeffrey Jensen Arnett and Elizabeth Fishel are authors of When Will My Grown-Up Kid Grow Up? Loving and Understanding Your Emerging Adult (Workman). Arnett, a research professor in the Department of Psychology at Clark University in Worcester, Mass., is a leading expert on emerging adulthood. Fishel is a writer specializing in family issues and the author of four nonfiction books.