Madam, Herpes is a viral disease. Once the virus enters your body it will cause symptoms like a short fever or a skin change which you might not have noticed back then. Following this phase it enters a phase where the virus will be in your body but won t cause any symptoms. It will wake up later when your body immunity is at a low like when you get a sore throat or bacterial infection. This time it ll cause painful ulcers and fever. I hope this answered your question about how it took time to show symptoms. When this might happen depends on people to people and their immunity. Regarding your boyfriend, the disease might ve spread to him from a partner he had before he met you. Like I explained, he wouldn t have known of this. An antiviral treatment for a few days will curb the disease. You can take a simple blood test to confirm the disease if you have any doubts. Hope I answered your query satisfactorily. Thank you.