Akademik

с жиру беситься
С ЖИРУ БЕСИТЬСЯ coll disapprov
[VP; subj: human or collect; usu. this WO]
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(of one who is deemed to have been spoiled by a satiated, idle life devoid of troubles) to behave in a fussy, capricious manner:
- X с жиру бесится{{}} it's X's plushy (cushy) life that makes him act so fussy (behave capriciously, act like this etc);
- X doesn't know when hefc well off;
- X is too well off for his own good;
- X does what he does for want of anything better to do.
     ♦ [author's usage] [Старый повар:] Вишь, черти проклятые! С жиру-то! Черти!.. (Толстой 3). [Old Cook:] See what the damned devils have done! It's their plushy life that makes them do this. The devils! (3a).
     ♦ Андрей натянуто рассмеялся: "Сейчас она скажет: вы ублюдки, с жиру беситесь". - "Вы ублюдки, - сказала Таня. - Я ваших заумностей не понимаю, а с жиру вы точно беситесь" (Аксенов 7). Andrei gave a forced laugh and said, "Just you watch. Now she'll tell us we're a pack of animals and don't know when we're well off." "Well, you are a pack of animals," Ibnya said, "and even if I don't understand all the ins and outs of your politics, I can tell you don't know when you're well off" (7a).

Большой русско-английский фразеологический словарь. — М.: ACT-ПРЕСС КНИГА. . 2004.