Like all forms of the herpes simplex virus, cold sores are highly contagious. Kissing and cold sores is risky business, because if you kiss someone while you have one or more cold sores, theres a significant risk of the other person being exposed to and infected by the virus.
What happens if I give my boyfriend head with a cold sore?
Herpes can be spread by having oral sex with someone who has active cold sores on their mouth, or genital sores. Therefore, even if both partners have no STIs, herpes can be spread to the genital area if someone has the virus around the mouth.
When is a cold sore healed enough to kiss?
In general, its best to wait for three to four days after the cold sore scab disappears before you kiss someone or engage in oral sex. This is because the herpes virus can continue shedding in the late stages of a cold sore healing, even if theres no viral fluid present.