Pass the Mustard... or Ketchup?

So my fiance hates ketchup and eats mustard on everything. This April fools day I am going to play a prank on her. One she won't be expecting.

I do apologize in advance for the small pictures. This is my first instructable and I used my cell phone to take pictures.

Step 1: Step 1

First thing you need to do is remove the cap from the mustard.

Step 2: Step 2

Stick the corner of a sandwich bag down in the mustard jar.

Step 3: Step 3

Fill the bag with ketchup

Step 4: Step 4

Replace cap to mustard.

Step 5: Step 5

Cut excess bag once you have the cap back on.

Step 6: Step 6

Have a camera so you can catch their reaction once they go to apply mustard and ketchup comes out.