Stiles and Derek start up a sexual relationship and it is "phenomenal"
! But seeing as how Stiles is a bit clueless and maybe a little bit sex dazed (can you blame him?), he finds himself in panic mode when Derek says those three magical words.
But don't fret. The characters are excellently depicted, the emotions are pretty poignant, the fluff is there for sure… I'm confident that your satisfaction is guaranteed.