A "dirty weekend" they call it.

"They" are the English.

"It" is sneaking away for a weekend with your lover. And Brighton, this quaint small city by the sea, is where was considered reique. Brighton was convenient to London, had discreet hotel porters and managers, and enough good accommodations and romantic settings for any serious lovers.

In fact, Brighton first became known and notorious because of love affair. The Prince of Wales, later to become King George IV, came to Brighton as a young man, liked the relaxed lefestyle, and eventually built the outragious Royal Pavillion, one of the most outstanding architectural eyesores in England, for his mistress.

Today of course, going off for a weekend with your lover is, if not accepted by everyone, certainly commonplace. But now most Englishmen take their women to the beaches of Spain or Portugal for the weekend. Brighton is nearly passe for these romantics.

But don't feel sorry for old Brighton. She is doing very nicely, thank you. For example:

A new $20-million convention center has just opened and is welcoming thousands of visitors.

A $100-million yacht marina has been completed and will soon be joined by a multimillion-dollar condominium and apartment complex.

The city is less than 30 minutes from the fast-growing Gatwick Airport where increasing numbers of international airlines, including Braniff, are landing. The close proximity is making Brighton more and more popular as a destination for visiting Americans.

Rather than fight the traffic from Gatwick to London (about an hour and a half) when you first arrive, you take a leisurely 30-minutes drive to Brighton, check into one of the delightful seaside hotels, and sleep off your jet lag to the sound of the crashing surf, not the blaring of London taxi horns.

Once you have recovered from you flight, you'll find Brighton has enough charm to keep you occupied for several days or even your entire vacation, if you have already done the London scene and don't see much excitement in fighting the hall-to-hall crowds of the English capital on a typical summer afternoon.

Everyone's first stop should be at "The Lanes," the original section of Brighton, which today is much the same as it was then (except, perhaps, for Dr. Blue's, a sex shop of some renown). The narrow, twisting streets house charming shops, with a heavy emphasis on antiques. You can nip in fo a nip at the Druid's Head, the oldest pub in Brighton, built sometime before, 1650, or have a bite to eat at English's a top-notch fish restaurant. The Lanes should keep you enthralled for hours, especially if you like to shop.

The main streer of Brighton faces the sea and along it sit the proud old hotels of the city. Places like the Grand and Old Ship and the Sackville, all reeking of dignity with their long terraces of cream-colored facades. Bow windows and canopied balconies and decorative ironwork overlook well-tended gardens. A bit of proper seaside living here, old chap.

And there are parks - 3,000 acres of them - to walk in, including Palmeira Square with its floral clock, and Preston Park with a special scented garden for the blind. And, of course, there is sport from tennis to five 18-hole golf courses.

Two reminders of the past jut into the sea from the seemingly endless beaches of Brighton - the Place Pier and West Pier. the West, which first opened in 1866, is presently closed to the public but the Palace Pier, built in 1899, is open and contains amusements and games galore. Also along the sea is a 100-year-old aquarium, Louis Tussard's Waxworks, and the seaside railroad, which will take you from Brighton to the new marina, reputed to be the world's second largest after San Diego's. From the marina, it's a brisk walk to Rottingdean (or you ride a number 110 or 113 bus), the quintessential English small village.

Rottingdean is so small-town English that it still has a village duck pond and, of course, the obligatory duck pond pub, this one called the Plough Pub. Cows still graze on the hillside above the village and one can imagine Rudyard Kipling, who lived here, laboriously penning his many novels by the pond. Today there is a modest Kipling museum and a toy museum in Rottingdean. All very quaint and low-key.

Just the opposite is George IV's incredible Royal Pavillion. It looks like a garish Taj Mahal on the outside, but is stuffed with Chinese furniture inside. The house was built by Henry Holland in 1787 and transformed by John Nash between 1815 and 1822 to the creature it is today.

The Royal Pavilion is perphas the world's greastes monument to bad taste and the past excess of British royalty. From the salon and drawing rooms to the Chinese corridor to the King's private apartments, the Pavilion simply overwhelms you with its overstuffed, overdone furniture, gilt and glitter, and emphasis on Chinese antiques - quite the rage then, as now. Perhaps the most interesting room is the splended "great kitchen," with its original mechanical spits and more than 500 pieces of copperware.

If you are in Brighton in July, August or September, the annual Regency Exhibition takes place in the Royal Pavilion, and it is then that the exotic interiors of the palace are seen to their best advantage.

During the summer months, the huge bantiqueting room is transformed into a sight fit for a king. The banqueting table is richly set with silver, gold plate, porcelain and glass of the period, and the sideboards are equally bedecked. Additional fine furniture and fresh flowers add to the myriad attractions of the Pavilion.

You can also visits the music rooms, which was badly damaged by fire in 1975, and watch the fascinating restoration program taking place very, very slowly - as is the British tradition.

You may not like the questionable taste and outrageous excess of the Royal Pavilion, but you must see it while in Brighton. At least the king's girl friend liked it, and together they started all those "dirty weekends." CAPTION: Picture, The Royal Pavilion, Brighton; British Tourist Authority photo.