You are not obligated to do anything sexual that you do not want to do. You are not obligated to sleep with anyone. You are not obligated to have unprotected sex with anyone.

If he wants to have sex again and you WANT to too, you tell him what you will and won't do. Set up your boundaries and make them clear. If wearing a condom is a big thing for you, make sure he knows you will not consider sex without it.