When did it become OK to not RSVP or write thank-you notes?

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Dear Prudence,

My partner and I host one or two parties a year at our home and the occasional dinner or brunch. We most recently hosted our annual Halloween cocktail party, where we invited several friends and colleagues who attended last year's event, plus a few new folks. My concern is that a number of the invited guests did not R.S.V.P. "regrets only" as indicated on the invitations (and in the follow-up e-mail), and the guests who did attend the party did not bother to write thank-you notes. We received three calls from the 30-plus guests attending. I am a moderately formal person who works as an art educator, and I am a Virgo. These two factors inform how I live my life (a bit structured with lots of fun). Are our expectations that people will R.S.V.P. and/or send a thank-you note unreasonable or old-fashioned? Are our experiences a sign of a new, less-formal etiquette?

—Y.R.B.

Dear Y.,

You are not old-fashioned. Things have just, uh, loosened up a great deal, and for whatever reason, many younger people have become, let us say, "casual" about manners. Prudie has many friends who've discussed being exasperated by inconsiderate people who can't be "bothered" to either respond to invitations or say thank you for gifts. (Prudie, herself, experienced a double whammy when she sent two gifts—for twins, obviously—and to this day does not know if the gifts arrived.) Charles Miers, the publisher of Rizzoli Books, was quoted in the New York Times as saying: "There's a feeling that etiquette is needed again. It's been so abandoned." And you might also throw in careless upbringing as part of the problem. So there's nothing wrong with you, cupcake. Your only recourse is to stop inviting the clods ... or sending them gifts.

—Prudie, pragmatically

Dear Prudence,

I hope you may be able to shed some light on how (or whether) I should give some advice to a friend of mine; let's call her "Callie." I met her in college and noticed pretty quickly that she didn't know how to "play the game" when it came to dating. Callie was notorious for immediately stifling the life out of a new relationship with stalkerlike behavior. She'd deluge each new suitor with phone calls, unannounced visits, discussions of long-term life plans ... she would pretty much inject herself into every aspect of his life. Needless to say, every man who showed interest ended up running away—screaming. Since she'd never had a relationship prior to college, my friends and I figured she would eventually learn from her mistakes. Well, we are now four years out of college, and Callie still continues to smother relationships before they can even get off the ground. Her last three "associations" (I can't really call them relationships) lasted no longer than one month each. Meanwhile, as friends acquire boyfriends or get married, she has become increasingly upset over how she feels she is being left behind. My question is this: As one of the married girls in the group, she asks me often what she's doing wrong. Should I answer?

—Train Wreck Bystander

Dear Train,

Yes, level with your friend because she asked. Try being her tutor/coach, and explain why her approach has been a relationship killer. Introduce the concept of being laid-back, pardon the expression. Of course it would be useful if she could get to the bottom of her need to gobble up any man who shows interest, but in the meantime it would be a good start if you could just wean her from her unfortunate blend of desperation, immaturity, and aggressiveness. If this girl could grasp the concept of "playing hard to get," even a 50 percent success rate could improve the situation.

—Prudie, skillfully

Dear Pru,

This is my dilemma. A couple months ago, my wife's ex-boyfriend from school called and informed me that my eldest daughter was his. Of course I didn't believe him, but to close him down, my daughter and I took a DNA test that proved that, indeed, I was the father. Now here's my problem. Little did I know that my wife and he have kept in touch throughout our marriage—nearly 30 years. In their correspondence she has sent him pictures of herself and cards and letters saying how much she has missed him. I've informed her that he sent me the cards and pictures and that he wants to get on with his own life. My problem is that I now feel that my marriage isn't worth much. I could have easily gotten over a physical affair, but trying to get over an emotional one is driving me nuts because that was from the heart. Please help.