Raven

I read a teen wolf fiction some years ago. I remember Stiles leaving beacon hills heartbroken after being pushed out of the pack (I think it was past Derek/Stiles) and a woman who's also a magic user in another town takes him under her wings and teaches him things he was supposed to learn under Deaton. She's part of a pack and someone of that pack asks Stiles on a date and down the road they marry happily and Derek is left a mess due to his own shortcomings

There's this vivid scene tho : The video of that guy proposing to Stiles goes viral and Lydia is the one who sees it first among the pack but almost everyone's already there and she has to show it to Derek. They knew he wasn't over Stiles but well...