Do I have to pick it off him cause I noticed the safe house shadow maker next to his door? And I did the pick ax favor for him.
No, you have to be a member of the thieves guild in Skyrim. Just get the quest for burning the bee hives, and a quest from Devon and from Vex, and you should get the option to ask him about the shadowmark.
is it giving you the option to ask about the symbol by his door? that's what opens up the task needed to gain access to his basemant. it wasn't the pick axe quest... but now i'm drawing a blank to what the other favor was.
and sister, lol. that makes more sense to me, thanks... i haven't found the other letter you're talking about, in the cave? do you remember what cave it was?
Not in a cave, but in the basemant of Grover's house. As I told windflower, you have to be a member of the thieves guild in Skyrim.