Heather Locklear/instagram. inset: getty
Heather Locklear has nothing but love for fiancé Chris Heisser on his 60th birthday.
The Melrose Place star, 59, marked the occasion on Thursday by sharing a throwback photo of Heisser, her high school sweetheart with whom she reconnected several years ago, alongside a picture of him in the present day.
The throwback shows a shirtless Heisser posing in blue cycling shorts, while he's pictured cuddling with Locklear's beloved dog, Mister, in the other snapshot.
"Happy birthday my love❤️," Locklear wrote in the caption.
Locklear and Heisser both graduated from Newbury Park High School in Los Angeles in 1979. The couple were on and off as Locklear battled substance abuse and sought help in rehab, but got engaged last April "as they were celebrating her year of sobriety," a family friend previously told PEOPLE.
"They are really happy together," the pal said following news of the engagement, adding that Locklear's family — including daughter Ava, 23, with ex Richie Sambora — "are all supporting her and excited for her."
"After all the fame, she found her way back to a simpler life with the boy she dated in high school," the friend said. "She found a silver lining. It's a wonderful feeling to know you got it right the first time."
Want to get the biggest stories from PEOPLE every weekday? Subscribe to our new podcast, PEOPLE Every Day, to get the essential celebrity, entertainment and human interest news stories Monday through Friday.
Locklear has had her ups and downs over the years. In 2019, she pleaded no contest to eight misdemeanor counts stemming from her two arrests in the prior year. She was reportedly placed on an informal three-year probation, and completed a court-ordered 30-day stint in a private rehab facility.
Last year, a source told PEOPLE that Heisser has been supportive of Locklear during her journey to sobriety.
"He always loved her and really believed she could get sober," the insider said. "After everything they went through, it's amazing to see that they stuck together. Heather has come such a long way."