a One Night Stand between Jason Todd and Harley Quinn would be an interesting angle for a Story about the Trauma caused by Joker and I'm surprised it hasnt happened yet
Profoundly creepy and indicative of overall poor mental health is how I would perceive that.

Doesn't help that they've toyed with several hero hookups with Harley in various realities. Including implied with Dick I've heard (haven't read), which I loathe the idea of.