feather your own nest
US /ˈfɛðər jʊər oʊn nɛst/
UK /ˈfɛðər jʊər oʊn nɛst/

1.
私腹を肥やす, 自分の利益を図る
to use your position or job to get money or other advantages for yourself, especially in a dishonest or unfair way
:
•
The politician was accused of feathering his own nest by awarding contracts to his friends.
その政治家は、友人に契約を与えることで私腹を肥やしていると非難された。
•
She was fired for trying to feather her own nest at the company's expense.
彼女は会社の費用で私腹を肥やそうとしたため解雇された。