Lyric discussion by girlofspirit 

Cover art for Peachy lyrics by Missy Higgins

"No of course you don't, of course you don't"; she's being very facetious about it, at the very least! She's pissed that their relationship seems to have rolled off him like water off a duck's back but she suspects that he's talking out of his arse because she's being quite sarcastic and tongue-in-cheek about the whole thing.