Alan told Walden, "Walden, Jenny is family. If you cross that line then I am not going to be your friend anymore. I mean I'm still gonna live here but I'm not gonna be your friend
That's a threat? I guess Alan can't make a more serious threat than that considering a more serious threat could result in him getting kicked out of the house. But he says he won't be Walden's friend anymore. Being Walden's friend is what's keeping him in the house. Alan would be friends with wanted criminals just to live in their house, rent-free.