Marry me! is a holodisk in Fallout 3.
Location
It can be found on the body of a female wastelander under a bench in the little "park" directly southeast of the Nuka-Cola plant.
Transcript
Sweetie,
Listen, I just can't wait any longer. I'm sending this letter, via courier, and I'm begging you to respond as soon as possible.
Why should we wait any longer? Forget our parents! Every day I sit here and watch my brother Kevin whither away from Radiation Sickness. Am I next?
I don't want to waste another second of my life. Let's just get married, and make a future for ourselves. Megaton, Rivet City, maybe even Tenpenny Tower. Who knows?
When I'm with you, I feel like I can do anything!
So marry me, you fool!