the horns
He cheated on me.
Soy un siervo por los cuernos de alguien mas?
Am I a servant by someone else's horns?
Acabo de enterarme de que mi esposa me puso los cuernos.
I just found out that my wife cheated on me.
She cheated on me.
And these are the horns.
Mary le puso los cuernos a su marido.
Mary cheated on her husband.
Debes agarrar el toro por los cuernos.
You must grab the bull by the horns.