Some guys have all the luck.
Kelly Emberg, Rod Stewart's fashion model girlfriend for most of the 1980s, posted the photo on her Instagram account.
Emberg is the mother of Stewart's daughter, Ruby, who is also a model.
"Can’t believe you are 40!" she enthused to birthday girl Kimberly. "You looked radiant last night! #birthdaybash. A mother’s reunion!"
In addition to Emberg and first wife Alana Stewart, fashion model Rachel Hunter --Stewart's second wife and the mother of two of Rod's children-- posed alongside Stewart's third and current wife, fashion model Penny Lancaster-Stewart, with whom he shares two sons.
Stewart has eight children with five women. The only one not pictured is a girlfriend with whom he had a child who was given up for adoption in the early 60s. They remain estranged, while the daughter has reportedly patched things up with her father.
Stewart, 74, is most famous for a string of 70s and 80s pop rock hits, including "Hot Legs," Do Ya Think I'm Sexy?" and "Some Guys Have All the Luck." He first hit the rock scene as the lead singer of the 60s outfit the Faces, alongside Rolling Stones guitarist Ron Wood.
Stewart, who was knighted in 2016 (making Penny Lancaster-Stewart his only wife who is also an official Lady), once said of his penchant for marriage and divorce: "Instead of getting married again, I'm going to find a woman I don't like and just give her a house."