But the actress who plays Dr Lexie Grey is anything but promiscuous.
As her character has fallen for everyone from Derek to George and now Mark, Chyler Leigh has lived a blissful married life; just a week after finishing filming for the sixth series, the 27-year-old gave birth to her third child, daughter Anniston Kae.
With Ellen Pompeo already knocked up, the writers decided against writing Leigh's pregnancy into the script so she spent much of the current series hiding behind medical equipment.
"It was one of those things where I'd show up and it's like, `Well, I don't know how long you're going to have me today, but let's hope for the best'," says the actress of working while heavily pregnant.
Though Grey's fans are used to the cast's incestuous on-screen hook-ups, it's not hard to see why creator Shonda Rhimes gave Lexie more than her share of romance.
Perched daintily on a tall director's chair on the show's austere Los Angeles set, Leigh looks classic and feminine: lily white skin, wavy hair - even the symbolic tattoos on her foot stand for family, love and faith.
It would be understandable if Leigh had had a hard time ingratiating herself on to the Grey's set.
Her character, Lexie, didn't fit in with the usual crowd.
When she first appeared near the end of season four, she was a lowly intern treated, as she said, like "livestock".
Even her half-sister, Meredith (Pompeo), didn't want anything to do with her.
She soon came to hold her own, however, revealing a photographic memory and gaining the nickname Lexipedia.
She also proved to be one of the more ambitious interns, practising certain procedures on herself and a friend.
"I think Lexie is insecure in a lot of ways about who she is and what she is doing.
"She's had a lot of tragedy in a couple of years, unexpectedly.
"And then there is something about Mark that helps mature her in ways that I don't think she's prepared for.
"So there has been a lot of growth and it's been really fun to see."
Leigh started out as a model, and at 16 got her TV break on the Aaron Spelling show Safe Harbour.
She met husband Nathan West when the pair starred in 7th Heaven, with Jessica Biel, and she followed that with a stint on a short-lived David E Kelley show.
Impressed, Kelley offered her a regular role as the feisty Claire Wyatt on law drama The Practice.
But even with all that experience, Leigh still finds the exposure since her arrival on Grey's a bit of a shock.
"Well, my character is definitely a resident now. It's strange even for me to say.
"There's an influx of doctors that come in through the merger this season.
"Everybody is at a point where it's like you never really know if you're going to get cut this week or next week and, if you make a mistake, if that's going to be your last mistake or, if you make a discovery, if that's enough to save you or keep you there.
"There's a lot of competitiveness, especially for the residents."
• The New Zealand Herald Grey's Anatomy screens Tuesdays at 8.30pm on TV2.
