After three days, fish and house guests start to smell, goes the old saying. That's not true in all cases. I've had my share of charming guests over the years, but I have also hosted those who did seem to grow scales and fins after a day or two.

My recent favorite was a relative having a crisis with his significant other while visiting for the weekend. He spent most of his time behind closed doors on the phone, except to take that show on the road when we went to restaurants. He ordered his food (and a large bottle of San Pellegrino) and then stayed in the parking lot glued to the phone while the rest of us ate. Since we can't ban those with the same genetics from the premises, he'll be back again - we hope with better manners next time.

Etiquette for guests is not really that complicated, but it seems to be a struggle for some. Almost everyone I asked for a house-guest horror story had one that quickly came to mind.

My friend Ellen has a sister-in-law who provides a story annually when visiting in Medford. She gives about 48 hours' notice of her arrival and then shows up with the family in tow. A few years ago, Ellen and her husband hosted a christening party for 50 people honoring the new child of her brother and that sister-in-law. The visiting family's contribution? A few dozen ears of sweet corn. "They drank all our liquor and replaced nothing," Ellen said. "They never opened their pocketbooks." When it was time to leave, the relatives wrapped up all the leftover food and put it in their suitcases. Then they asked Ellen and her husband to please mail their gifts and clothing to them. At least they said please.

Jane, from Haddonfield, had extremely demanding guests whom she and her husband entertained nonstop. Yet the couple never offered to help. They sat in the kitchen talking endlessly, while the hosts slaved over the meals. The parting hostess gift was an elaborately wrapped framed photo of the visiting couple and their child. Thanks for the memories.

Megan, of Flourtown, an Inquirer reader who has hosted her share of guests, still shudders when she thinks of one couple. The man was an old friend of her husband's. When Megan was leaving for work, the female guest was sitting in the kitchen "wearing a very skimpy nightgown that was also quite transparent. Then she hugged me goodbye closely. Did I mention that I had just met her?"

All these women enjoy having guests and I do, too, but there are standards of behavior when you are the visitor.

"Show up with a few nice gifts, treat your hostess to a meal, help out, clean up," said Patricia Dorrian, an Inquirer reader from Springfield. "Treat the guest room like your own. Give your host some privacy."

I agree and would add that you should offer to pick up a few groceries and pile up your linen and towels when you depart. It is also polite to give your host a little time without you under foot. Guests who expectantly wait for the next event put a lot of pressure on the host or hostess.

Jane's husband is from Europe, so they have a revolving door of guests and find most of them to be a pleasure. They appreciate those willing to head into Philly on their own and see the sights. "We explain that if we have to see the Liberty Bell one more time we'll go crazy," she said. A little independence from the visitors goes a long way.

It is polite to be gracious and to welcome people into your home, but it is also their responsibility to be good guests.

But hosting is not for everyone. When I asked our friend Rich for some advice for guests, he simply said, "Stay at a hotel."