Hello and welcome to healthcaremagic There must be an exchange of body fluids in order to transmit most STIs. Though some STDs can be transmitted by skin-to-skin contact e,g genital warts etc. STDs are most commonly transmitted by sexual contact. You cannot contract an STD unless and until you get intimate with someone. Various modes of transmission of an STDs (including non-sexual) are: -Sexual transmission (genital-anal, genital-genital, oral-genital/anal) -Skin-to-skin contact (i.e., kissing, non-penetrative sex, body rubbing) -Sharing of needles and needle stick injuries -From a pregnant woman to her unborn fetus, or to infants during vaginal delivery or through breast milk -Infestations (scabies and pubic lice) can also be transmitted through shared clothing, bedding, linens etc. So you need not fear about acquiring an STD through a nick/cut sustained during shaving. Hope this helps Regards