Well, Lucien Lachance doesn't pay you a visit unless you've murdered someone. In my current game, I'm playing as a good guy and haven't encountered him for this reason. My old character though was eager enough to join up. I'd never kill him though, partly for sentimental reasons but also because it closes off the Dark Brotherhood off to you forever and those are some of the coolest quests in the game.

Mr burke is cool but he is NOTHING compared to lucien. NOTHING!
i practically [censored] myself with passionate sadness and anger when

What else was I supposed to do?
Some creep blathering about his mother comes into my room in the middle of the night, draqed in something that looks like extremely unflattering black curtains: I panicked!
It's his fault, really. He could've stopped by at a more reasonable time with a pamphlet or something, instead of trying to be all debonair and cliché.

I killed him one time just to see if I could haven't done it since.