The 33-year-old superstar and 38-year-old musician have been friends for years. Brian got married in 2013 to his wife Angie Pontani and they have one child together.
A source spoke to Us Weekly about the kiss and said it was totally harmless.
“There is nothing to see here. Gaga is a performer, and it was a playful, harmless part of her act. She and Brian have had an incredible friendship for years and see each other as family,” the source said.
You can see a video of Lady Gaga smooching Brian Newman on Twitter, and you can see photos of Brian in the gallery.