Jonathan Bennett had risen to fame in his teen years when he was cast as Aaron Samuels in the film Mean Girls.
Colton Underwood announced his engagement in February 2022 after less than a year of dating, having been first linked in September 2021.
Josh Hartnett stepped away from the spotlight to focus on his mental health.
The newly-engaged pair are yet to talk about the wedding.
Alaina Scott's biological mother is Dawn Scott, who is the twin sister of Eminem's ex-wife, Kim Scott, 46.
She was pictured running errands in Los Angeles while wearing a diamond ring on her left ring finger.