Talk about a great date night!
Foxx was on hand to join Streisand in singing The Sound of Music's "Climb Ev'ry Mountain," which the pair performed to an enthusiastic crowd. They also performed the song at Streisand's show at the venue on August 11.
Witnesses say that Holmes supported her man after the show, spending time in his dressing room.
"They left from the dressing room area a few minutes apart from each other but she was hanging out in his dressing room with him after the show," a witness shared.
The pair, who have been dating for almost three years, are very rarely seen together in public, and their relationship was only revealed last year. Holmes was previously married to Tom Cruise, and the pair share 10-year-old daughter Suri, although reports say Suri has not seen Cruise in years.
"Jamie is someone she can trust and have fun with," a source said of Holmes last year. "She's getting everything from Jamie that she didn't get with Tom."
"Katie is so in love," another source added. "She is all about Jamie."