Green’s Dictionary of Slang

1. (orig. Aus., also piggie) unpleasant; greedy.

1894		Coburg Leader (Vic.) 27 Oct. 2/5: They Say [...] The captain of one of Hemingway’s teams has turned ‘piggy’ and sings ‘I won’t play with you any more’.
1914		A. Brazil Leader of the Lower School 129: ‘When I handed her my box of candied fruits, she picked out the very biggest!’ ‘How piggie!’.
1918		A. Brazil Patriotic Schoolgirl 81: ‘[I]t would be perfectly piggy to wear the same serge dress from breakfast to bedtime’.
1957		‘Neville Shute’ On the Beach 202: It’s so piggy here in the winter – nothing but rain and gales.
1958		E. Dundy Dud Avocado (1960) 194: Why are they all being so piggy?
1991		B. Stewart Broken Arse I v: You mean Piggyscrew, don’t ya?

2. (US gay) sexually abandoned [stereotype of porcine sexuality].

1972

B. Rodgers Queens’ Vernacular 64: lewd, vulgar, pornographic [...] Piggie (‘Did things get piggie after ten?’).