It takes two to tango is an expression that is used when you want to emphasize that both people involved in a difficult situation must accept the blame or that an activity needs two people who are willing to take part for it to happen:

For example, we succeeded because we worked together. After all, it takes two to tango.

I don’t care who started it; it takes two to tango.

Don’t blame me for the argument. It takes two to tango!

It takes two to tango, and we must all take responsibility for our contribution to the dynamic.

We will never reach an agreement unless we sit down for a discussion. It takes two to tango.

Tradução: ninguém faz nada sozinho, precisamos trabalhar juntos, quando um não quer, dois não brigam, não se mantém um relacionamento sozinho.