The actor posted the trailer for Off the Rails on his Instagram and expressed why the movie was so special to Preston.
"Off the Rails is Kelly's last film- she was very proud of it and of all of the wonderful talent that she got to work with in it," Travolta captioned the clip. "It is available in UK and Ireland theaters starting this Friday July 23rd! @offtherailsfilm @bklproductions."
Off the Rails follows four friends in their 50s who recreate an inter-rail journey across Europe, but this time 18-year-old Maddie is taking her mother's place, fulfilling her dying wish. Dame Judi Dench, Jenny Seagrove and Sally Phillips co-star. The movie began filming in February 2019.
Preston died in July 2020 after a two-year battle with cancer. The actress and Travolta shared three children; 21-year-old daughter Ella and 10-year-old son Benjamin, as well as the late Jett, who died in 2009 at the age of 16.
Over the last year, the Grease star has paid tribute to his late wife, most recently on Mother's Day. Travolta took to Instagram to share a pair of snapshots of Preston, alongside an emotional memorial celebrating her legacy.
"Dearest Kelly, you brought into my life three of the most wonderful children I have ever known," Travolta wrote. "We love and miss you. Happy Mother’s Day."
The two first met when they went in for a screen test together for the 1987 comedy The Experts. However, they were just friends as she was married at the time to actor Kevin Gage. They later began dating in 1990 and tied the knot in 1991.
During an interview with ET in 1998, Preston marveled at how good a kisser Travolta truly was, sharing, "My husband's got great lips, really great lips. Even if he wasn't my husband, I'd really like kissing him."
She even admitted that she hated watching her husband perform in steamy scenes with his co-stars. "I know it's just a film but if the kissing's lasting a little too long, I don't like it," Preston told ET with a laugh during a press junket for her 1997 rom-com, Addicted to Love. "I'm sorry, but it makes me [think], 'You kiss me like that! That little romantic thing, that's ours and ours alone!'"