My husband wants me to “get over it and move on”.

I(42F) caught my Husband (64) doing some things he shouldn't be doing, as a happily married man. It happened a while back but I have found a couple things since then. He told me he didn't see anything wrong with it because there was no emotional attachment! He would not want me to do anything though. He wants me to forget and forgive without any problem at all. I don't think I can do that. So confused on what to do! He swears he doesn't remember any of it, so he's either lying or he has some health issues with memory loss? He has had a rough couple of years, health wise.