According to a study published in Psychology of Women Quarterly, "the results suggest that seemingly innocent overtures – checking women out or complimenting them on their appearance – have remarkably negative effects on women.”  You probably already knew that, but this provides some evidence to back you up if you ever need it.

[Thanks and credit to ivehadtoomuchtothink for sending this in!  If you want to submit to Facts for Feminists yourself, you can do so here.]