Infidelity advice

My partner was caught 3 years ago talking and lying about this woman. I know they exchanged pictures. We’ve been trying to work through things since. I recently saw a post saying that men don’t pay attention if they don’t care. I know I shouldn’t of asked him bc it only hurt my own feelings, but I needed to know if he cared about the pictures. I asked what color of underwear she was in and he knew instantly. The picture was sent 3 years ago… how would y’all feel in this position? Should he of been able to remember the color after 3 years? Advice please and please be kind. I’ve been really going through it…

Edit: I found out about the talking 3 years ago. I found out that pictures were exchanged during that time a couple months ago, so it’s bringing old feelings back.