Dear Amy: My best friend of 25 years is having an affair. I'm devastated. We raised our kids together, our families spent holidays and vacations together, but most of all she has been my soul sister and confidante.

I have tried to offer support, listening and trying to be nonjudgmental. But I keep tripping over the fact that my dad cheated on my mom. The day I found out was the worst day of my life. I spent years angry, developed a severe eating disorder and needed years of therapy.

I love her children like my own and don't want them to go through that trauma.

I have lost respect for her and feel like it's changed everything. Am I being judgmental and not a true friend?

What's my job as a best friend? Must I show my support, no matter what? I want this friendship to weather this storm, but I need advice on this "besties" role.

Amy says: Friends tell each other the truth, and a deep and abiding friendship can withstand the tumult that honesty sometimes brings on.

It is possible, and preferable, to deliver your radical honesty without attaching judgment to it. You do this by using "I statements," and by owning your personal distress about this. For example: "I'm upset about this. I'm worried about your family's future. My father's infidelity destroyed me as a child, and this is bringing up a lot of painful memories for me."

I also think it's totally OK to convey to your friend, "I'm unsure of my role, here. I don't feel comfortable being your confidante about this affair. I want you to know that our friendship is important to me, and I don't want to lose it."

It would be natural for you to step back a bit as she goes through this whirlwind.

Mistakes can be forgiven. Hurts can be healed. But once you really lose respect for a person, it's game over.

Wedding blues

Dear Amy: My daughter said that she got the wedding of her dreams. Family and friends came from far and wide to celebrate her nuptials. It was lovely in every respect, and both her mother and I were thrilled that things went as she wanted.

However, she was so caught up as the center of attention that she ignored the common tradition of greeting each table and saying a few words to their guests. Even after I asked her to speak to the guests, she ignored my brother and sister and their families entirely.

My brother let me know the next day how hurt they were. Her mother and I were crushed. We had no idea that she had neglected them.

Of course, I strongly recommended making amends to these relatives. But I feel I failed as a parent and failed my daughter by not being aware of this fault at that time.

I thought that we had raised her better. She's no kid; she's 34. What would you suggest I add to our conversation?

Amy says: Rather than add to your conversation with your daughter, I suggest that you take away something: your own sense of embarrassment, shame and any responsibility you might be tempted to assume for her rudeness.

You prompted her at her reception to do the right thing. She ignored the prompt. She is an adult. This behavior — whether it was an oversight or deliberate — is her responsibility.

You are correct that she owes her spurned relatives an apology. Not only is greeting one's guests basic wedding etiquette, it is also simply a "nice" thing to do, and for many people would be instinctual.

Send questions to Amy Dickinson at askamy@amydickinson.com.