Robert Brown|Matty Healy Joins Phoebe Bridgers Onstage as She Opens for Taylor Swift on Eras Tour

...Ready for this?Robert Brown

Matty Healy just went from being a spectator to a surprise guest performer on Taylor Swift's Eras tour. At the "Blank Space" singer's concert in Nashville May 6, the 1975 frontman joined her opening act Phoebe Bridgers onstage to perform guitar during her set.

His appearance at the show comes one day after he attended Taylor's previous concert at the same venue as a VIP guest and spectator and amid recent rumors that allege the two are dating, which neither musician has confirmed nor denied. E! News had previously reached out to their reps for comment and has not heard back.

As seen in a fan's Twitter video, which has gone viral, members of the crowd cheered loudly when Phoebe introduced Matty by name after their performance at the May 6 show at Nissan Stadium. The two singers and her band members also wore matching skeleton onesies.

Both Phoebe and Taylor have collaborated with Matty on music before. The "Bad Blood" singer joined him onstage for a surprise appearance at The 1975's show in London in January, two months before she began her Eras tour and three months before it was reported that she and Joe Alwyn had broken up after six years of dating. Neither she nor the actor have commented on the split, although she did implement a cryptic change to her tour set list.

This is not the first time Taylor and Matty have sparked romance rumors. They first spurred such speculation in 2014, and the following year, Matty denied in a radio interview that the reports were "fake."