It's an emotional roller-coaster for Lexie when Grey's Anatomy returns tonight.

Chyler Leigh tells TV Line that the opening scene of this week’s episode, featuring Lexie and Jackson, picks up where we left off. And that means it gets “a bit steamy ... not, like, literally steamy - it’s not a shower scene again! - but it involves other equipment.”

What the ... never mind. As for where she sees this new couple going?

“I think they support each other, care about each other and it’s easy for one another to talk to each other about whatever they need or whatever want - things like that.”

“They’re both in the same place in their lives, and they also have the physical attraction to one another, so ... it’s Grey’s Anatomy, so they want sex,” the actress adds.

Interactions between Lexie and Mark, meanwhile, have been few and far between, largely because of the plenty complicated baby drama he’s got going with Calzona.

How does Chyler assess that situation?

“Lexie got pretty rocked by the whole thing," she says. "It was a breaking point for her, so her involvement [with all of that] so far hasn’t been too much.”

Tensions from that are likely to boil over: “There’s a run in between [them] that’s a bit awkward,” Leigh says of the baby shower. “It’s one of those moments.”

By season’s end, Leigh reckons, “Something will have to come to a head." In the meantime, Lexie and Jackson will be singing a happy tune. Sort of literally.

“I’m singing ‘Breathe (2 AM)’ by Anna Nalick, and Sarah Drew (April) and I both do the chorus on a song called ‘Grace,’” the mother of three shares.

“And In ‘Walking On Sunshine,’ by Jesus Jackson, I do a part in there.”

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.