I am for Tom. True ones would never end. At least till you get vivid memories in your mind, even in case of betrayal...

Hahaha....for me they end there, where start relationships:)))) or in case betrayal... 

If you mean with someone of the opposite sex, then I would say that line is crossed when there is physical intimacy. When you are very close to one another's lives, but you also are <em>very </em>touchy beyond just hugging. 

I share the same viewpoint that Tom, why the end?

I think that true friendships never end.