will regret it
You will regret this.
Yo, sólo soy otro tonto soldado yendo a un lugar del cual se arrepentirá.
I'm just another foolish soldier going to a place I'll regret.
— Avatar (2009)
He will regret this.
She will regret it.
Déjeme tranquilo o se arrepentirá.
Leave me alone or you'll regret it.
— Ladrón de bicicletas (1948)
He/She will regret it.