Kim Dobson can chuckle about it today, now that enough time has passed. But it was far from a laughing matter the first time her oldest son Matthew brought a girlfriend home from college for an overnight visit. Absent any daughters -- and having heard horror stories from friends about similar visits that had gone terribly wrong -- the McCandless mom wasn't sure how to negotiate this rite of passage.

Where was she going to sleep?

Is it OK to set a curfew?

What about alcohol?

And she thought simply sending him off to college was tough on the nerves!

The fact that her son, like most college-aged males, was less than forthcoming with information about his friend's likes and dislikes, didn't help matters. "He was like, 'Mom, don't worry about it. It's not a big deal.' "

Except, of course, that it was.

"You always want a guest to be comfortable," notes Mrs. Dobson, who works as a teacher's aide at North Allegheny's Hosack Elementary. "But when you don't know someone it's hard to anticipate things."

In the end, she and husband Jim needn't have worried. Neither Matthew, now 28, nor his girlfriend pushed the envelope on sensitive issues, paving the way for a pleasant visit. If anything, the girlfriend ended up being easier to deal with than her son, who worried his parents would tell embarrassing stories about his childhood.

No doubt about it, the holidays can be tough. Along with gift shopping, decorating and cooking elaborate meals, many of us have to deal with family dynamics that get swept under the rug the rest of the year -- the second cousin who drinks too much, the uncle who loves to argue politics, the sister who never lends a hand in the kitchen. To throw someone new into the mix only compounds the stress.

Add the fact that this unknown person could be the mother or father of your unborn grandchild -- or at the very least is someone important enough to your child that he wants you to meet her -- and the importance of making a good first impression takes on a new significance. You don't want to burn any bridges.

To some extent, how parents and child tackle this new territory depends on how you deal with life in general; if yours is the kind of family that talks openly you'll probably have no problem saying what's on your mind. If you're quiet, you're more likely to ignore it, notes Paul Friday, chief of clinical psychology at UPMC Shadyside.

The bottom line is it's your home and you get to say what is and isn't acceptable behavior under your roof -- even if you know it's a different story back at college. It is, though, important to set boundaries beforehand, says licensed marriage and family therapist Megan Norris -- say, how late they can stay out or whether they can have a beer with dinner -- or there could be some uncomfortable surprises or hurt feelings.

Wing it, and you may end up feeling like you're in a replay of "The Family Stone," the 2005 holiday flick in which an uptight New Yorker (Sarah Jessica Parker) meets her future parents-in-law and discovers they can't stand her.

"You have to ask yourself what kinds of things do you want resolved prior to them walking in the door, because it's always harder to deal with the unexpected," says Ms. Norris, founder and clinical director of Relationship Resolutions, a psychotherapy practice in Green Tree.

Rather than hand your child a set of ground rules, however, make it a dialogue instead of a directive so that she feels like her concerns are being addressed. Who knows? Maybe they'll raise an issue you haven't thought of, such as how their younger siblings tend to eat breakfast in their underwear. (Robes, please!) And allow for a little flexibility. Now that your child is off on his own, it's not unreasonable for him to expect a bit more freedom.

Also, don't forget to talk to younger siblings about the upcoming visit, both to alleviate any fears and to help set the tone. They may be imagining the worst-case scenario when in reality the visit probably will be fun, says Dr. Friday. If it isn't, tell them you still expect them to treat their sibling's friend with respect and kindness. In other words, make her feel welcome.

Your college-aged child should understand that he or she has to be considerate of others' feelings. For instance, it's not fair for him and his girlfriend to monopolize the family TV, computer or video game system, or to use the kitchen for a tryst.

Speaking of displays of affection, one of the most uncomfortable subjects to broach is sleeping arrangements. Many college students today are sexually active and might expect to share a bed on holiday visits. Parents, meanwhile, may consider unmarried people sleeping together sacrilege. Initiating that conversation will put everyone comfortably on the same page, says Ms. Norris.

"Chances are, they're having the same thoughts and questions and might not be sure how to address them," she says.

Similarly, if you're not comfortable with your underage child drinking, say so.

Curfews, which make a college student feel like a little child, can also prove touchy. Instead, note Annie's Mailbox columnists Marcy Sugar and Kathy Mitchell in an e-mail, ask them to be home by a certain (lenient) hour out of consideration for the rest of the family. Explain how staying out until the wee hours wakes people up and worries the parents. If they're going to be out later than expected, they should call and let you know. Then, give the pair a key and tell them to be sure to lock up when they get home.

"This says you trust them to behave like adults," the columnists write. It also eliminates the need to worry about what to do if they break curfew, since they don't actually have one.

While you may hope your child and her friend join you for breakfast, lunch and dinner, insisting they eat every meal with the family can be too much. So don't get bent out of shape if they decide to go out. Guests should be present at the holiday meal or other special events unless they have told you in advance that they have made other arrangements.

If the visit takes place over Christmas or Hanukkah, make sure you have a gift for your child's friend so she doesn't feel left out of the festivities. Something along the lines of a book, gloves, scarf or picture frame would be appropriate. And pick up the tab if you go to a restaurant or movie, or ride the incline to Mount Washington for a birds-eye view of the city. In short, treat your child's guest as you hope someone else's parents would treat your son or daughter.

The difficulty in all of this, of course, is maintaining a sense of normalcy when everyone is feeling anything but normal. You don't want things to seem forced or out of sorts, but at the same time, there is this different dynamic that can't help but play a role.

Mrs. Dobson's advice? "You just have to take a deep breath and have a good time because the stress levels during the holidays are high enough." Oh, and dress up a little more in the morning to avoid looking like a slob and allow yourself to chill out with a glass of wine.

Heightened stress levels notwithstanding, what's fun about these types of visits is that they help tune a family to the inevitable changes of growing up.

"It ends up being a wonderful dynamic because it forces everyone to adapt," says Dr. Friday.