For Grey's Anatomy's Alex and Jo, Small 'Bumps' -- and a Big Blast from the Past -- Lie Ahead

Grey's Anatomy Season 10 Jo AlexIt’s all over but the consummating.

As Grey’s Anatomy opened Season 10, Alex and Jo repeatedly acted on a summer hiatus’ worth of pent-up passion, yet ultimately let cooler heads prevail in the name of saving their first time together for the right place and time.

RELATED | Grey’s Anatomy Season 10 Premiere Recap: You Win Some, You Lose Some

“They’re sort of juvenile” in their can’t-keep-their-hands-off-each-other-ness, Justin Chambers observed to TVLine at the ABC drama’s 200th episode party.  “They’ve got a lot of growing up to do. And I think that we’ll keep playing with that because it’s fun to watch. What they do for a living [as doctors] is so serious, it’s nice to lighten up and have fun.”

But if Grey’s has taught its doctors anything over the years, it may be to get while the gettin’ is good, seeing as love never flows too smoothly for too long in the halls of Seattle Grace Grey Sloan Memorial.

“It’s a new relationship, and with new relationships come a lot of bumps,” Camilla Luddington noted. “It’s not easy for them.”

RELATED | Jessica Capshaw Talks Grey’s Infidelity and the ‘Long, Load Road Ahead’ for Calzona

Then again, romance has never come easily for Alex — enduring as he has over the years heartbreaks both big (Izzie!) and small (Dr. Lucy Fields).

Might Jo be the one to eclipse all others? Is this destined to be the love of Alex’s life? “It could be,” Chambers allowed, “but that’s a writers thing. As the actor, you’re thinking one thing, and then they’ll turn it around on you. We’re as surprised as the audience, at times, with what direction the story goes.”

Regardless of any superlative attached to the nascent romance, one thing is not up for debate: the on-screen chemistry between the pair’s portrayers. “You can’t intellectualize it. It’s either there or it’s not,” Chambers said. “Luckily, they do such a good job with casting — Linda Lowy has brought in so many great people on our show — and Camilla’s great. She just loves her job, and you want to work with actors that want to be there, that appreciate what they have and have fun doing it.”

RELATED | Grey’s Anatomy‘s Cristina Quandary: 4 (Mostly) Plausible Exit Scenarios for Yang

Looking ahead, before the Alex/Jo pairing even can be considered for any record books, it will have to navigate that stickiest of wickets — a blast from the past, in the form of Alex’s abusive, drug addict father, played by Dexter‘s James Remar.

“Jo wants to be very supportive — she’s trying to be there for him and be a good girlfriend,” Luddington previewed. But the relationship between Alex and his estranged dad, she said, is in and of itself “very tricky.”

Fortunately for Alex, Jo — having, like he did, gone through the foster care system — comes from a place of shared perspective.

“Jo’s going to be there to kind of pick him up and tell him to get on with it,” Chambers revealed. “He’s dealing with somebody that has the same sort of background that he’s had, and that should deepen their relationship.” (With reporting by Scott Huver)

Want more scoop on Grey’s, or for any other show? Email insideline@tvline.com and your question may be answered via Matt’s Inside Line.