• С КЕМ ПОВЕДЕШЬСЯ, ОТ ТОГО И НАБЕРЕШЬСЯ
[saying; occas. only the first half of the saying is used) you unwittingly adopt the views, habits of a person with whom you socialize or are on friendly terms: ≈ he who (that) lies down with dogs gets up with fleas; he who (that) lives with a cripple learns how to limp; you cannot touch pitch without being defiled; [when only the first half of the saying is used]
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⇒ it's catching.
♦ [Леонидик:] Он любит тебя. Он сам сказал мне это. [Лика:] Ого!.. Берёшь пример с настоящего мужчины? [Леонидик:] С кем поведёшься... (Арбузов 4). [Leonidik:] He loves you He told me. [Lika:] Oh! So you're behaving like a real man! [Leonidik.] It's catching .. (4a).
Большой русско-английский фразеологический словарь. — М.: ACT-ПРЕСС КНИГА. С.И. Лубенская. 2004.