The A Star is Born star also posted some fun snaps of the evening to her personal Instagram account. "I love the cure, felt my old self come alive tonight what a show @thecure," she wrote.
Gaga, 33 and the 37-year-old sound engineer first sparked rumours of a romance after they were spotted in the midst of a major PDA whilst having lunch at Granville restaurant in Studio City, California.
'She and her guy wanted to sit outside. They didn’t seem to care that people could see them,' a source told Us Weekly at the time.
Gaga – real name Stefani Germanotta – is believed to have first met Horton last November when he joined the singer’s team ahead of her Enigma residency in Las Vegas.
The Born This Way singer broke up with her talent agent fiancé Christian Carino, 50, in February amidst speculation about her close relationship with A Star Is Born co-star Bradley Cooper.