I'm gonna go out on a limb here: if your idea of a great proposal is to do it at a death metal concert, I'm going to venture to say you're not mature enough for marriage.

what was her cue to just show up on stage? the endless drum solo?

I've worked a few music venues in my day. There was all kinds of depressing shit like this. A group of three ladies came to a dance party one night to celebrate one of their birthdays. The room capacity was 600 and they were the only people there. (the venue closed a few months later)

That being said, she is probably the most attractive person I have ever seen associated with death metal. Album cover models don't count.

Is this Metalron?