Former Beverly Hills, 90210 star Jason Priestley still regrets ending his romance with Blake Lively's big sister Robyn as the hit teen soap was taking off. The actor and the Karate Kid, Part III actress were together as his star was on the rise and he's still sore about the fact he never gave the relationship a chance. He tells Access Hollywood Live, "I just ended things very abruptly with Robyn for no good reason. I just found myself in a situation with this show... and I didn't really know what to do, what was happening, or how to make this all work... and I just felt I needed to be as unencumbered as I could be. "God bless her, I think she understood it better than I did at the time... It was a difficult time." The former lovers are now happily married - Lively to actor Bart Johnson and Priestley to fitness guru Naomi Priestley, and he insists it all worked out for him. He adds, "She's (Naomi) super... She's incredibly engaging and very smart."