Aventus Aretino won't talk

[God's Wet Diaper]

I went to Windhelm to try and start the Dark brotherhood questline again, but to my surprise when I got into the kid's house he wasn't performing the black sacrament. I tried reloading, playing without any mods, starting several new games and nothing seems to work.
Does anyone know what I could do?

[Eternie]

You need to get the quest to see him first ... You should have heard guards of people in an Inn talk about the aventino kid to get the quest. Then and only then will he be doing the sacrament.

I'd suggest you load a save before trying to talk to him. Then go to Taverns and ask for rumours.
As you may have glitched that quest otherwise.

[God's Wet Diaper]

I know that, I got the quest first of all
But bah, I don't know