Q:

Russian equivalents of the French expression "pour un oui ou pour un non"

Tu ramènes toujours tes complexes ethniques, pour un oui ou pour un non, dans toutes les discussions, même les plus anodines. 

{literally}: You always dredge up some complex about your ethnic origin, be it for a yes or a no, in virtually all discussions, even of the most harmless nature. 
{more naturally}: You always dredge up some complex about your ethnic origin at the drop of a hat in virtually all discussions, even of the most harmless nature. 

This hyperbolic expression is used to refer to someone's annoying tendency to insist on doing something with no apparent rhyme or reason, as if on a whim. 

Pleurer, c'est un truc de fille à ses yeux, comme si elles avaient le droit de pleurer pour un oui ou pour un non. 

The way he sees it, crying is a girls' thing -- as if they had every right to shed tears over any little thing. 

How is this idea commonly/idiomatically expressed in Russian? 

A:

I think чуть что would fit best here:

В любом разговоре, даже самом невинном, ты, чуть что, начинаешь бередить свои комплексы по поводу пятой графы
Как по нём, плач — девчачья тема, им, типа, можно чуть что — и в слёзы.