aha...

Main Entry: vir·tu·ous
Pronunciation: 'v&r-ch&-w&s, 'v&rch-w&s
Function: adjective
Date: 14th century
1 : POTENT, EFFICACIOUS
2 a : having or exhibiting virtue b : morally excellent : RIGHTEOUS
3 : CHASTE
synonym see MORAL

If you look at no 2 it clearly shows you how piglet is virtuous...
"having or exibiting"... have you ever seen piglet wear any clothes???... I thought not
therefore he is clearly an exhibitionist... and voila... that makes him virtuous...
thank you ladies and gentlemen... thank you