Akademik

ездить верхом
ЕЗДИТЬ ВЕРХАМ на ком coll, disapprov
[VP; subj: human or collect]
=====
to exploit s.o. whom one has subjected to one's will, use a person for one's own ends, make s.o. do what one wants:
- X ездит верхом на Y-e X pushes (bosses, orders) Y around;
- X walks all over Y;
- [in limited contexts] X has Y wrapped around X's little finger.

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