Do you know a way to check/know someone's penis or vagina size by his / her face? I have a clue and I used it on some people, approximately 70% results were true. If you want to check a male penis size. See his nose size and make an approximation of penis. If you want to know a female vaginal opening. Check her mouth / lips opening and guess it with vaginal opening. May be it look awesome, but wana try to apply and take a survey.