Next week’s episode will reveal the identity of the Benefactor. Which is actually not as simple an answer as it might appear. It brings up big questions answered in the final three episodes—events that go back to the very first season of Teen Wolf, with secrets revealed about what happened after the Hale fire.
—  Jeff Davis teases what’s to come in episode 4x09 ‘Perishable’ and more (source)

I wonder if they ever FaceTime when everything isn’t going to hell and just talk about things. Lydia would pour her heart out on things that have been bothering her to Stiles. And Stiles would listen to her rants and give her advice. And maybe some nights Lydia didn’t want advice, maybe she just wanted someone to listen to her and she knew Stiles would.