What is that all about?

It becomes a symbol of their love. A vow sworn only to each other. Fidelity, if you will.

...If I'm not mistaken, one of the great writers of the modern era participated in several double suicides, but kept coming out the only survivor.

That is... well... another kind of intense...

Well, he did call himself "No Longer Human".

Bah. Drama queen.

At least become immortal first, then we'll talk.