Here in Cologne it is a new tradition, that loving people put an padlock on the Hohenzollern Bridge. With that symbol they can lock their love and throw the key in the Rhine river, so you can't open it again and your love is locked forever.

Plus - With my scad file, you can make your own love padlock with customized initials on it. 

I made the padlock keyless. The mechanic inside of the body will click in the shackle just one time. So you can't open the padlock again. If you print your love lock, you don't need any supports and rafts.