It's just like the title says, you ask will you be my (insert something here) and the next poster will answer yes or no then asks will you be my (insert something here) and so on.
Here is an example:
will you be my candy cane?
will you be my pillow?
Though there are a few rules that you must follow
1. All BMGf rules apply here
2. Have Fun!
Will you be my Pokemon Trainer?