Sylvester Stallone and daughter celebrate happy life milestone

Sylvester Stallone’s eldest daughter, Sophia, is engaged to her boyfriend Michael Sheehan!

Sophia, who turned 30 on August 27, revealed the happy news on Instagram by sharing a series of intimate photographs from Michael's incredibly romantic proposal.

"Forever with my best friend," she simply captioned the post alongside an infinity symbol.

The beautiful black-and-white photographs put Sophia's dazzling diamond engagement ring firmly in the spotlight, with the bride-to-be placing her hand affectionately against Michael's face as the pair kissed.

Another photograph captured the moment Michael got down on one knee, surrounded by an elaborate display of white roses, candles and flower petals.

Sophia could be seen wearing a fitted white mini dress and strappy heels, while Michael wore relaxed blue-grey shirt and cream trousers.

The newly engaged couple later posed together against the nighttime city skyline, with Sophia proudly holding up her left hand to reveal her new ring.

Sophia's younger sisters were among the first to celebrate the news.

"YAYYYAYY MY FAVORITE PEOPLE!!!!! Crying! So happy I love you both!!!" Sistine, 28, wrote beneath the announcement, while 24-year-old Scarlet declared them "THE MOST BEAUTIFUL FIANCÉES!!!!!!!"

Paris Hilton also joined the well-wishers, writing, "Congratulations love."

Sophia later posed with her famous parents, Sylvester and Jennifer Flavin, with the 80-year-old Rocky actor beaming beside his eldest daughter as she showed off her new ring.

The engagement marks a particularly significant milestone for the famously protective father of three, who has made no secret of just how seriously he takes his daughters' dating lives.