Lady Gaga and Taylor Kinney Make a Rare Red Carpet Appearance at the Kennedy Center Honors

"We had such a wonderful time," the singer says

It's not often that Lady Gaga and Taylor Kinney walk red carpets together.

But special occasions call for special exceptions, and Sunday's event fell in the latter category. When the couple of three years attended the 37th Annual Kennedy Center Honors in Washington, D.C., the "G.U.Y. singer" turned heads wearing a floor-length white gown with a matching cape. The pop star, 28, added some of her signature sparkle via two rows of rhinestones, which were placed over her bleached brows.

Gaga performed "If I Ever Lose My Faith in You" and later shared a photo with Kinney on Instagram. "We had such a wonderful time at the Kennedy Center. We both care so much about the arts staying alive and respected. Celebrating all the honorees was an honor for me to be a part of and watch," she wrote.

Other performers included Bruno Mars, Esperanza Spalding and Bruce Springsteen. President Barack Obama and First Lady Michelle Obama presided over the star-studded concert event, which honored musicians Al Green and Sting,actor Tom Hanks, ballerina Patricia McBride and comedienne Lily Tomlin.

In another Instagram caption, Gaga called "If I Ever Lose My Faith in You" a "classic song about keeping faith as the times and people change. I loved singing with the band last night for STING, Trudie, The President and the First Lady. We brought some grit and fire to the stage, and I loved every second of it."

The outing was a sure sign that Gaga and Kinney's romance is getting more serious.

But are they ready for marriage? "Well, you know," Gaga demurred on SiriusXM's The Howard Stern Show Dec. 2. Asked about their rumored commitment ceremony, she said, "Uh, no. You heard a lot of things."

Gaga and Kinney, who met on the set of her 2011 "Yoü and I" music video, have bonded over their shared love of art. "I can't really imagine being with anyone other than who I'm with right now," she said. "He's extremely creative. When it comes to his work, he can be quite introverted. He likes to just study and study and sit with his thoughts. We really connect in that way. We don't do the same thing."

The "Applause" singer continued to praise the 33-year-old Chicago Fire actor, saying, "He's extremely talented...What I do feed off is my ability to have an intelligent conversation with him about how it feels to be a creative person, because a lot of people don't always understand you. They think you're weird."

CBS will broadcast The Kennedy Center Honors on Dec. 30 at 9 p.m. ET/PT.