The ‘Dancing’ hitmaker took to her Instagram account to share a black and white image of herself indulging in a sneaky smooch with the GQ magazine creative director, and he posted the same picture on his social media site.
The pair both wrote in their captions: “Birthday girl.”
Kylie also shared a risqué naked snap of herself with only a diamond-encrusted guitar protecting her modesty, and admitted she was “thankful” for her life so far.
She wrote: “And so a new decade begins. How thankful I am for the opportunities life has afforded me. 50….. Let’s go!”
Paul was among the guests at Kylie’s star-studded birthday bash at London’s Chiltern Firehouse hotel and restaurant.
Her ex and former ‘Neighbours’ co-star Jason Donovan was also in attendance at the party, along with singers Rick Astley, Mel C and James Blunt; TV presenter Alan Carr, comedian David Walliams, actor Rhys Ifans, and Pretenders founding member Chrissie Hynde.
Kylie also had a Ramsay Street reunion with former ‘Neighbours’ actor Guy Pearce at the bash.
Earlier this month, the pop princess – who split from 30-year-old actor fiancé Joshua Sasse last year – admitted she was “deluded” into thinking her romance with the ‘Galavant’ actor was worth saving.
She said: “I think we all know that things were not going great in my relationship, but, you know, when you’re kind of deluded and you’re thinking maybe, maybe … maybe this needs saving.
“Turns out, it didn’t.”
Kylie has also admitted marriage was never a “goal” of hers.
She said: “My love life is often painted as being a failure and I don’t think of it that way.
“Yeah, there’s not that postcard moment but, is that for everyone? Is that for me?”
Discussing marriage, Kylie added: “It was never that goal that I felt like I had to reach.”