Ruminating about the past?

I have been with my boyfriend for 10 years and of course have dealt with ROCD for years I would have thoughts of other people and feel so guilty not realizing until very recently it’s ROCD. I have ocd but did not know of this type. Anyways about 6 years ago I had a guy friend that I liked the attention of but nothing else and I know it is wrong this was a long time ago I have stopped and me and my boyfriend have talked about it. But I remember I would check his story frequently and thought the guy looked cute and sometimes go check his story again on Snapchat. I don’t know why I did it, I did not think he was attractive really until he posted a picture in a different angle so I thought he looked cute. I haven’t thought about it until a week ago and now I’ve been feeling so guilty like I cheated or something and I feel like I have to tell my boyfriend or else I’m keeping something from him and I’m a terrible person