'Arrow' star Colton Haynes is engaged to Jeff Leatham

See how Cher helped!

ByABC News
March 13, 2017, 9:59 AM

— -- Actor Colton Haynes and Jeff Leatham are engaged!

The duo posted photos and videos from the proposal, which culminated with fireworks, in Cabo San Lucas, Mexico.

Haynes, 28, who starred in "Arrow" and "Teen Wolf," posted a shot of the two kissing with the caption "I SAID YES!!!" then gave a shout-out to the iconic Cher for her help.

"Thank you @cher for the beautiful 'I got you babe' proposal lead in, you sounded incredible as always :) The most special night of my life," he wrote in another post.

Leatham, a celebrity florist and an art director, posted a video from his close friend Cher, who said, "You know what it is. You know what you have to do now," referring to the proposal. She also wanted the duo to call her afterward.

Everyone was celebrating the couple's big night, including actress and Haynes' best friend, Ally Maki.

"MY BEST FRIEND IS ENGAGED!!! This will forever be the best FaceTime call of my life. Overjoyed with love and emotion for my soul mate baby and ride or die on the happiest day of his life. Colt this is the moment!!" she wrote.

Haynes and Leatham went public with their relationship earlier this year, and they were posting fun photos from their Mexico trip before the question was popped.