The Gallaghers were on their best behavior at Emmy Rossum's wedding!

The cast of the Showtime hit Shameless came together to celebrate Emmy, aka Fiona Gallagher, as she tied the knot with longtime boyfriend and Mr. Robot creator Sam Esmail. William H. Macy and Jeremy Allen White both suited up for the occasion, while Shanola Hampton captured some epic behind-the-scenes moments from Emmy's NYC wedding.

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"We've been together a LONG time! We are blessed to share in one another's huge life chapters! Thank God for this family," Shanola, better known as Veronica Fisher on the show, captioned a pic with her co-stars outside the wedding reception.

Inside Emmy made sure to save a dance for her on-screen dad, and had some photo booth fun with her guests.

Wearing a custom-made Carolina Herrera wedding gown, Emmy was a far cry from her now iconic TV character. Her friend and designer Dorie Golkin Smith shared a photo of the brunette beauty on her big day in the designer dress, writing, "No words can describe the love and joy that filled this weekend."

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The couple tied the knot at the Central Synagogue before heading to the Guggenheim Museum for the reception.

Emmy, 30, recently opened up about her relationship and revealed the romantic way Sam, 39, popped the question.

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"We have a tradition of reading the ‘Modern Love’ section of The New York Times every Sunday,” says Emmy. “I do a dramatic reading of it for him. Even if we’re not in the same place, I read it to him over the phone. Then one weekend we didn’t read it—I don’t remember why exactly—and the following Friday he reminded me that we hadn’t," she told Vogue. "So I got in the bathtub with the ‘Modern Love’ section as he’s posted up on the sink.

She continued, "I didn’t notice any kind of ring in his pocket, and I began to read the article, and the story is about a director who falls in love with an actress, and I started to think: Huh, that’s strange. And then I realized that it was our love story… So I got out of the bathtub wrapped in a towel, got cold, and then got back in the bathtub because the stories are quite long. And then by the time I finished the story he was down on a knee in the bathroom, with me in the tub.”

Congrats to the happy couple! For more photos of the cast at the wedding, check out the gallery below!