PROMPT: Maybe set after the scene when Childermass declines Strange's invitation to join forces - perhaps they come to some other arrangement? Filthy as you like. Maybe over a table, looking at pictures of the King's Roads...? Bonus points for a bit of a tussle to decide who does who.

A kinda fill although it doesn't quite hit all the requests of the OP, but does involve a blow job:
http://jsmn-kinkmeme.dreamwidth.org/1273.html?thread=692217#cmt692217