KJ and actress Britt Robertson (who previously played in films like Tomorrowland and The Longest Ride) had previously had a history of romance— but only on film.
The two appeared as a couple in the 2017 film A Dog’s Purpose, which could have been the root of the pair’s still-evident fire. After gathering, KJ and Britt were spotted at the Entertainment Weekly Comic-Con embracing, holding hands, and even kissing while hanging out with his co-stars from Riverdale.

Britt was still dating Teen Wolf star Dylan O’Brien when the two filmed A Dog’s Purpose. Following six years of dating, the couple broke up in 2018 and was most recently partnered with Graham Rogers, who starred at the Quantico of ABC. The two had even posted on Instagram until December 2018 about each other. The posts have since been withdrawn, a true indication of a partnership that is over in the 21st century.