Until and unless you lead by example, perhaps

世間の口に戸は立てられない
(Seken no kuchi ni to wa taterarenai; “You can’t put a door on society’s mouth”)

Definition:

You can’t stop people from talking. You may not like it when people repeat or discuss rumors or criticism (about you), but there’s no way to force them to actually stop.

Breakdown:

We begin with the noun 口 (kuchi), “mouth.” The question of what mouth is answered by joining it to the noun 世間 (seken), “the world” or more specifically “society,” with the associative particle の (no). This noun phrase is then marked with the particle に (ni) as the location of the following verb phrase.

The verb in question is 立てる (tateru), which can have a wide variety of meanings depending on the context, but which here means “to shut.” The verb appears in negative potential (“can’t”) form. What are we talking about that can’t be shut? A door (戸, to); specifically a traditional Japanese sliding door, marked by the topic particle は (wa).

Notes:

There are many commonly-used variations for this saying. The negative ending may be changed from ない to ぬ (nu) or ず (zu), for example. 世間 may be replaced with 人 (hito), “people,” or 世間のくち with 開いた口 (aita kuchi), “open mouth.” The particles may be changed from に to には (ni wa) and from は to が (ga). And somewhat unusually, since in this context 立てる implies a door being closed, tateru may be written as 閉てる without any change in meaning or pronunciation.

Example sentence:

「あの腐敗政治家は毎日暴れ、記者たちに罵詈雑言を浴びせるが、その汚職が広く知られていく一方だ。世間の口に戸は立てられないことを早く理解すれば自分の尊厳の一かけらを保てるだろう」

(“Ano fuhai seijika wa mainichi abare, kisha-tachi ni barizougon wo abiseru ga, sono oshoku ga hiroku shirarete iku ippou da. Seken no kuchi ni to wa taterarenai koto wo hayaku rikai sureba jibun no songen no hitokakera wo tamoteru darou.”)

[“That corrupt politician rages and hurls abuse at reporters every day, yet knowledge about his corruption keeps on spreading. Perhaps if he realizes quickly that you can’t force people’s mouths shut, he might be able to preserve a shred of his dignity.”]