The Grey's Anatomy wedding of Callie Torres (played by Sara Ramirez) and Arizona Robbins (Jessica Capshaw) takes place on Thursday night's episode.

The episode will include a Catholic storyline and the women will tie the knot wearing white gowns during an outdoor ceremony. (Visit lesbian entertainment website for preview photos.)

“They are special TV 'I love you' vows,” writer Stacy McKee told E! Online, “but I did use fairly traditional Catholic vows as a template because that's Callie's background. And it was important to Callie to have a lot of tradition in her wedding. And as you can see there are white dresses and lots of flowers. No white leisure suits here. It's full-on wedding.”

Ramirez and Capshaw recently spoke about Callie's Catholic upbringing and how it relates to their big day.

“Callie was raised Catholic and she loves her church and she loves her God, and that's OK,” Capshaw told

“Arizona in the beginning of the episode has been an empowered woman who knows exactly who she is and has known all her life.” Ramirez said. “Callie has been on a different journey; she's investigating it and experiencing it and figuring it out as she goes, especially with her parents who are very Catholic – her mother in particular.”

“Callie starts to understand and embrace the notion that God is everywhere and that you don't have to be in a church to share God's presence of love and acceptance and to have a union with someone and a wedding and ceremony that means everything to you,” Ramirez added.

Last month, Grey's Anatomy creator Shonda Rhimes took to Twitter to defend the storyline.

Grey's Anatomy is not the first ABC drama to feature the wedding of a gay couple. In 2008, Kevin Walker (Matthew Rhys) married his boyfriend Scotty Wandell (Luke MacFarlane) on the network's Sunday night drama Brothers & Sisters.

In both cases, the shows are set in states where gay marriage is not legal. Grey's Anatomy's Washington and Brothers & Sisters' California recognize gay and lesbian couples with domestic partnerships.