If you never cheated on him and you have been with him for a year or so, most likely it's him who infected you and gave you that genital wart
. Some people (like 30-40%) have
asymptomatic infection, means they have
the virus, they can pass the virus, but never show any symptom. Some people even believe the number is way beyond 30-40%. Who knows your boyfriend had the virus already but he simply one of these people (who never got any genital wart).