Knotting is one of my favorite kinks, but I don't necessarily like all what comes with ABO for the current pairing of my heart. Cue, Magnus' dick being his warlock mark for all the knotting a girl could want :D
I wanted to write this last year, but then I got sidetracked during the build-up, and ended up with jewelry kink and body worship and Magnus hiding his knot.
So this year is the year \o/