See also pigsney in Todd's Johnson, where one quotation has the form pigs eie.
(obsolete), late 14c., endearing form of address to a girl or woman, apparently from Middle English pigges eye, literally "pig's eye," with excrescent -n- from min eye, an eye, etc. See OED for explanation of why this might have been felt as a compliment. In a pig's eye! as an adverse retort is recorded from 1872.