If you use a condom while sucking, you will greatly reduce the risk of any STIs that can be passed this way. However, since Syphilis, HPV and Herpes are spread through genital to mouth contact and because condoms do not cover all of the genitals, there is a small chance these STIs could pass.
Herpes can easily pass while kissing, and there is some risk for Gonorrhea, HPV and Syphilis if you are “deep kissing” or using tongues during kissing, but they are not commonly passed this .
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