This post contains spoilers about last week's episode of This Is Us . Just when we were starting to take sides in Kevin's (Justin Hartley) love triangle, This Is Us threw a serious wrench into the mix. Toby (Chris Sullivan) thought he was helping Kevin decide between Olivia (Janet Montgomery) and Sloane (Milana Vayntrub), but Kevin had a different romantic interest in mind. We learned from birthday-party flashbacks that Kate's childhood best friend, Sophie, had a major crush on Kevin when the Big Three were 10. It looks like those feelings didn't go away — when Kevin shows up at present-day Sophie's (Alexandra Breckenridge) door, we learn that she was once married to Kevin, but they're now divorced. Hartley spoke to Entertainment Weekly about the shocker, and what he thinks made the marriage go south. When interviewer Dan Snierson asked Hartley if Kevin was to blame for the relationship's dissolution, Hartley said that "good people do bad things." "A lot of times, especially in careers where it's really very competitive, you start to put that ahead of relationships and people, and I think that also had something to do with it," Hartley said of Kevin's failed marriage. "He lost himself a little bit, and he lost his way." That doesn't mean the door is totally closed for Kevin and Sophie, though. After all, she did agree to meet with him in last week's episode. "It affected him a lot if he's going to go back to her," Hartley said of Kevin and Sophie. "He's in love with her." Hartley also declined to take a side in the Olivia-Sloane debate, instead praising both Montgomery and Vayntrub's acting. Check out the full interview over at EW