You're going to regret this

What someone says to attempt to shy someone away from a decision they're about to make, especially one that's grandiose. This can be said whether this decision is simply something the person saying this phrase disagrees with, or if it's actually bad. Ironically enough, after saying this, the person who is being targeted with this phrase oftentimes never actually regrets anything.

Person 1: JESUS CHRIST. YOU'RE A STUPID CRYBABY. I REGRET EVER CROSSING PATHS WITH YOU. WE'RE NOT FRIENDS ANYMORE.
Person 2: Oh yeah? Just you wait! You're going to regret this!