The singer halted the band's show in Detroit, Michigan on Saturday (30Mar13) to introduce a fan called Scott and his boyfriend Dominic to the stage, and the audience was stunned when he dropped to one knee to pop the question.
Manson knew of Scott's proposal plan in advance after receiving a message from him via her Facebook.com page, and she helped out by giving him free tickets to the gig and backstage passes.
Dominic accepted the proposal, and the singer cheered and clapped as the couple embraced, before posing for a picture with them and the rest of the band.
Manson told the crowd, "They said they knew they were meant for each other in this life because they both had Garbage Cds... Thank you for your indulgence."
The rockers then played their song Vow in tribute to the newly-engaged couple.