Jennifer Lopez treated her holiday party guests with a sweet serenade.

On Saturday night, the Grammy winner, 54, was joined by party guest Jenifer Lewis for a special rendition of “Have Yourself a Merry Little Christmas.”

Lopez and her husband, Ben Affleck, threw a star-studded Christmas bash at their home in Los Angeles, with Lewis, 66, Margot Robbie, Michael B. Jordan and Lily Rabe among the many guests in attendance.

During the celebration, the Black-ish actress sang the Christmas classic alongside the Hustlers star.

“There was so much love in the room,” Lewis wrote on X (formerly known as Twitter) after a video of the performance circulated. “Great party baby girl♥️♥️♥️ Happy Holidays Everybody♥️.”

In the video, the two are seen embracing behind a grand piano and a smaller keyboard. Lopez kept her arms wrapped around the Sister Act actress as the two sang together.

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“They threw a really fun party,” a source told PEOPLE on Sunday. The insider shared that Lopez led the partygoers into singing Christmas carols late into the night.

While Lopez and Affleck were meeting with friends separately while also hosting, the source went on to say, “They were both in such good spirits.”

The house was decorated in holiday decor with a huge Christmas tree at the entrance. “The kids were all there dancing and having a great time, especially the twins and Violet,” adds the source of Maximilian “Max” David Muniz and Emme Maribel Muniz, 15, and Affleck’s daughter with Jennifer Garner, Violet Anne, 18.

Garner, 51, and Affleck, 51, also share Seraphina Rose, 14, and Samuel, 11. Lopez shares her twins with ex-husband Marc Anthony.

This is Affleck and Lopez’s second holiday season together after marrying in 2022. They were engaged in 2003 and 2004, and reconnected romantically in 2021.