Can anyone tell me how I have been infected with oral herpes?

Ok last month was the first time I got an oral herpes outbreak and I dont know how that is possible since I knew my ex boyfriend for a while now and he has never had any oral herpes outbreaks. Does that mean that sometime last month somehow I was infected by someone kissing me on the cheek or sumthing like that? Is i possible that my current bf wud get oral herpes outbreak too even though we have not kissed since I had my first oral herpes outbreak. Please help someone.