Before Mom, Pop and tots wear out their welcome ...

IT seems ideal. You call your friends/cousins/parents to tell them you are planning a visit to their part of the world, and their immediate and enthusiastic response is, “You must stay with us!”

How great is that? Free digs; access to a fridge, stove and washing machine; perhaps a little baby-sitting; and all that lovely bonding time. Perfect, right?

Could be. Or not. Depending on the people, place and things involved.

Here’s the thing about kids: In theory, they’re great. In theory, they eat only at mealtimes, help set the table and take off their muddy shoes before they come in. They don’t open drawers in other people’s bureaus or try to climb the bookshelves. They amuse themselves in ways that do not always involve television or an adult’s direct attention. They don’t scoot under the bed looking for Grandpa’s gun or hide out in the attic coloring in the pages of Uncle Paul’s comic-book collection.

Sometimes children are like this in reality as well. But sometimes they aren’t.

So when someone makes the generous offer of putting you and your family up, you need to ask yourself: How well does this person understand what he or she is offering?

Or, in plainer language, when was the last time a 5-year-old spilled an entire gallon of milk on their floor in an effort to “do it myself”?

Far-flung relatives, including grandparents, may have raised children of their own, but amnesia is a key part of parenthood. It’s what allows people to have more than one child. It also makes it possible for otherwise mentally acute grandparents to say things like, “You and your brother never fought like that” and “I don’t know what the problem is; you kids were always in bed by 7 o’clock.”

When my parents were both living, we spent several weeks-long vacations with them in Ireland. But there was never any question of our staying with them when we visited at their home. Although their house was technically large enough, it would have been a tight squeeze psychologically. My father’s health was not great, they were not the best child-proofers in the world, and both were used to a measure of peace that children, even infants, tend to shatter.

So we stayed in a nearby hotel. That way, we could spend most of the day with the ‘rents but everyone had a built-in break at the end of the day. No one took it personally because it wasn’t about whether my parents loved us or the kids; it was about what would foster the best visit.

This doesn’t mean visiting folks with no children or grown children can’t work. When we took Danny and Fiona, then a toddler and an infant, to visit my cousins in Chicago, I got one look at their immaculate, art-filled home and blanched. No way were we making it out of there without doing serious damage to the familial relations. But my cousin Mary, who in a former life must have run a successful B&B;, had made sure there were so many toys and books for the kids to play with that they never considered turning the statuary into a battlefield. Our visiting took place almost exclusively in the kitchen, family room and back patio, which kept the living room safe without making it prohibitively off-limits.

If your potential host does have children, odds of a successful trip are better if they are close in age and temperament to yours and the parenting styles involved are at least compatible. (I could not survive two minutes in a house where yelling was considered deviant behavior.)

If you don’t know what sort of kids your host has, it helps to be ruthlessly honest. When a friend of mine proposed that the kids and I bunk with her family, she was much more worried about how our 5-year-old daughters would get along than about how her older boys would treat my 7-year-old. The boys, she said, were easygoing, but her daughter was tough. I had to laugh. I told her I would see her “tough” and raise her “stubborn.” The girls were instant buddies.

Whenever someone invites us to stay with them, I describe my children in the same honest way I do when I am researching a vacation rental. They are high-energy kids who don’t always stop bouncing on the bed the first time you tell them to. They have traveled enough to know that another person’s house is not a hotel and that certain things are off-limits. But when you stay in one place for a few days, it’s hard not to feel like it’s home and relax a little. And relaxation seems to have a direct relationship with scattered socks and cereal spills.

So before we go stay with friends or relatives, I always make my hosts swear that if, for whatever reason, they start feeling this is not working out, they will say so. And if we can’t fix it, we’ll get a hotel, no hard feelings.

Though I believe in the whole “love-me, love-my-family” ethos, that doesn’t mean anyone’s obligated to put us up for a week.