You have to ask him if you want a guarantee, but I think he is checking to see if you are still friends. Sexual activity even just kissing changes things and he probably wants to sort out where your relationship stands now. He is acting responsibly if he wants to talk about what happened so talk about this together. I don't think he changed his mind. I think he wants to deal with this since it was so out of character for him. See what he says regarding this incident and you will know where things stand. From this point on, don't engage in activities such as this if you don't want to ruin the friendship. He may regret it and ruin the friendship that you have.
If this has been helpful press accept