共謀する
JN1;JVE
conspire together / plot / plotting together / partners in crime / collude with / plot with a person / playing into a person's hands / conspiring with a person / play into a person's hands / conspire / in league with / co-plotting / conspiracy / collude / plotting with a person / conspiring together / co-plot / put-up job / in cahoots with / plot together / colluding with a person