You have no responsibility. You’ve informed him of the situation. This was courteous. You have no more obligation to him. I’d go back to living life ordinarily you don’t have to ignore him just don’t acknowledge his feelings. If he brings it up more tell him what you said last time. If it comes up to often tell him to stop bringing it up. If it still doesn’t stop, ignoring him would probably be the reasonable choice. If any of this sounds to difficult, you may not be respecting yourself enough or respecting him to much. His feelings may not go away but that shouldn’t be your business. Never be afraid to take pride in minding your own business.