As many comments posted to talk about the Singapore Law, and some people suggested to make a site of "Sluts Checker", please refer to the Singapore Law as below:
Word or gesture intended to insult the modesty of a woman
509. Whoever, intending to insult the modesty of any woman, utters any word, makes any sound or gesture, or exhibits any object, intending that such word or sound shall be heard, or that such gesture or object shall be seen by such woman, or intrudes upon the privacy of such woman, shall be punished with imprisonment for a term which may extend to one year, or with fine, or with both.
Defamation Act - Section 4Slander of women.
4. Words spoken and published which impute unchastity or adultery to any woman or girl shall not require special damage to render them actionable."
Disclaimer : This piece of information is just to share to our Singaporean ladies about their rights in Singapore. No threatening intent to SG Guys inferred.