Back in July, 22-year-old KJ was snapped kissing his 29-year-old co-star Britt Robertson, at the Entertainment Weekly's Comic-Con 2019 party in the US.
The two were spotted packing on the PDA while large crowds watched on, going as far as sharing a kiss, according to E! News.
The pair weren't shy in having their arms around one another while walking together around the event, even mingling with Riverdale co-star Camila Mendes at times.
KJ Apa and Britt Robertson met when they acted together in the 2017 movie A Dog's Purpose.
They are set to star together as love interests in their new film I Still Believe, which is a sequel to the 2018 movie I Can Only Imagine.