Get a friend to call her up to say you're in hospital after a horrible accident.
When she's gets to the hospital, another friend (dressed as a doctor) leads her to your room. Lie there, with the duvet over your head and lay perfectly still. The doctor then asks her to confirm the identity of the body. As he peel the duvet back, reveal you with a rose between your teeth. Leap up and kneel, proposing to her there and then. Then all the other doctors and patients get up and do a choreographed dance sequence for about 15 minutes.
( Edd: The Unfunny Try-Hard Edgelord, Wed 22 Jun 2011, 15:10, archived)

Then actually die, for the ironic lolz

( Edd: The Unfunny Try-Hard Edgelord, Wed 22 Jun 2011, 15:10, archived)

actual tears of mirth!
I cant see it going terribly well, but this is powering to the top of my likely scenarios!
(Unstable-Dan looks like that bloke out of Scream, Wed 22 Jun 2011, 15:41, archived)