Look closely and you’ll see that this is a seduction scene, but what makes the dialogue unconventional is the specific tactic by which Jack is trying to “seduce” Lee. 

Jack tries to show Lee how vulgar, witty and literary he is in order to win her friendship.  Lee, by bringing up Jack’s closet pissing, calls him out for not being the cool guy he’s desperate to be… BUT it’s over being a loser that these characters genuinely connect. Seduction complete.