Q.We have been dating for several years now, and frequently socialize with anot

This other gentleman has a zest for life, and, unfortunately, overtly portrays some of this zest toward his live-in girlfriend in a most public and embarrassing manner. She also demonstrates the various yearnings very capably.

They do this not only at semi-formal dinners, but everywhere else as well. Are they insecure and trying to prove something?

Sadly, they practice these unabashed animalistic tendencies in front of single friends who are in various stages of unattached, and often lonely, singledom.

No one seems to know what to say. It is interfering with our socializing, and I recently had to refuse a weekend to New York because of this.

How does one broach the subject? I have asked my boyfriend to talk with his friend, but he is uneasy about doing so.

A.Miss Manners does not deal in such concepts as insecurity as an excuse for bad manners. This implies that they cannot quite help themselves, and should be regarded with some tolerance.

However, she can tell you in plain language, with no allowances made for the fact that there are motivations why your friends are behaving rudely.

They are showing off, with the intention of pointing out to everyone else, single or coupled, that they have a pleasure others don't. As you point out, they are achieving this effect.

Nature has added an illogical sense of uniqueness to each person's experience of the ordinary joys common to all humanity -- including not only falling in love, but the happiness of having a baby or grandchild and watching the child develop. Added to the pleasure itself is a certain (totally false) smugness that no one else has ever been so much in love, or had such a wonderful child.

As we all take turns at this, a certain amount of indulgence is required as long as the victims of delusion keep their behavior within reasonable bounds. One should indeed make a fuss over a couple's getting engaged, and do one's share of marveling over other people's perfectly ordinary children.

When they exceed the bounds, as when parents subject unsuspecting guests to their children's recitals, or bridal couples want to put something into the wedding ceremony that will let the guests know there is a physical aspect to their union, they must be stopped.

The bounds for a young couple in love, when in the company of others, go no further than occasional deep glances, furtively pressed hands, and that sort of thing. It seems particularly obvious in the case of a couple actually living together that there is ample privacy to do whatever else they wish to do, and that if they are willing to come out of their quarters at all, they should be prepared for proper socializing.

Miss Manners suggests that you and your friends give these people the isolation they seem to require. If they complain of being dropped, the explanation is, "Well, you always seem to want to be alone," and, if pressed, "You know, we're all pleased you're happy, but it is a trifle gross to watch."

The wording is important: If you suggest that you are "bothered," or anything else that will be eagerly interpreted as envy, you will only encourage them.