PARIS — In his dark comedy of 1893, “A Woman of No Importance,” Oscar Wilde has Mrs. Arbuthnot, a respectable woman with a secret past, remark knowingly: “A kiss may ruin a human life.”

It can also, apparently, ruin the stone blocks of a tomb.

Recently, descendants of Wilde, the Irish dramatist and wit who died here in 1900, decided to have his immense gravestone cleansed of a vast accumulation of lipstick markings from kisses left by admirers, who for years have been defacing, and some say eroding, the memorial in hilly Père Lachaise Cemetery here. But the decision meant not only cleaning the stone, a flying nude angel by the sculptor Jacob Epstein, who was inspired by the British Museum’s Assyrian figures, but also erecting a seven-foot plate glass wall to keep ardent admirers at a distance.

Family members and some friends of Wilde have welcomed the step. The writer Merlin Holland, who is Wilde’s grandson, said the message was clear. “We are not saying, ‘Go away,’ but rather, ‘Try to behave sensibly,’ ” he said in a phone interview. “I’m sure there will be criticism,” he added....