Unexpectedly, Stiles goes into heat after babysitting triggers his omega hormones.

Derek being an alpha, of course has the compulsion to provide all sorts of services. Yep.

I could have totally gone without the whole lactation aspect of this fic but it's A/B/O and you know how I feel about that.

Despite a rough beginning and ending, the middle part is what counts the most… and it was hot with KNOTTING.