Callie and Arizona's Relationship Surgery on 'Grey's

Grey's Anatomy lesbian couple Callie (Sara Ramirez) and Arizona (Jessica Capshaw) seem to have finally reached a stable, happy phase of their relationship. Capshaw, however, warns fans shouldn't assume things will stay that way for long.

"This is a drama, of course," Capshaw tells TVGuide.com, "there will be conflict." The source of that conflict might just be Callie's waffling  sexual identity. She's already shown how easily she hops beds from guys to girls and back again. As Capshaw says of Callie, "her playing field is vast."

Capshaw says the immense pressure on the characters on Grey's Anatomy tends to push them into "mistakes" in their personal lives. "They kiss the wrong people, they sleep with the wrong people," Capshaw says. "We get to see how things unfold and if there's forgiveness.” Callie is no exception to the rule, Capshaw says. "Callie could find another guy or girl."