「原形畢露」

(pos:語句)
<explanation>
yue:露出真面目
eng:to unmask and expose the full picture
<eg>
yue:佢喺靚女面前扮有禮貌，唔夠兩分鐘就原形畢露。 (keoi5 hai2 leng3 neoi2 min6 cin4 baan6 jau5 lai5 maau6, m4 gau3 loeng5 fan1 zung1 zau6 jyun4 jing4 bat1 lou6.)
eng:He pretended to be polite in front of pretty girls, but he soon exposed his true character in less than two minutes.