Derek doesn’t really have to tell anyone, when it happens, except for Laura.
Most of his, and Stiles’s, friends have facebook, and so they already know.
Laura doesn’t have facebook. She has her reasons, which Derek has dismissed (he knows facebook is selling his information to corporations, okay? The difference is, he doesn’t care), and all it means is that he has to go and tell her the news in person.
Derek is at least a little bit convinced that Laura doesn’t have facebook because it forces Derek to have actual conversations with her.
hi Stiles had a serious girlfriend after his dad died called Marina and they were together for two years and he didn’t mention her to Scott at all because she was special and he didn’t know how to describe her and he bought a ring but they broke up and she’s the only serious relationship he’s ever had and he’s decided they’re not for him but that’s really not her fault i’m avoiding that trope like the plague